diff --git a/halo2_gadgets/src/sinsemilla/chip.rs b/halo2_gadgets/src/sinsemilla/chip.rs
index ce78a241f7..281b07d77a 100644
--- a/halo2_gadgets/src/sinsemilla/chip.rs
+++ b/halo2_gadgets/src/sinsemilla/chip.rs
@@ -95,18 +95,27 @@ where
     }
 }
 
+/*
+trait SinsemillaArgs {
+        type Hash: HashDomains<pallas::Affine>,
+    type Fixed: FixedPoints<pallas::Affine>,
+    type Commit: CommitDomains<pallas::Affine, Fixed, Hash>,
+    type Lookup: DefaultLookupRangeCheck,
+}
+*/
+
 /// A chip that implements 10-bit Sinsemilla using a lookup table and 5 advice columns.
 ///
 /// [Chip description](https://zcash.github.io/halo2/design/gadgets/sinsemilla.html#plonk--halo-2-constraints).
 #[derive(Eq, PartialEq, Clone, Debug)]
-pub struct SinsemillaChip<Hash, Commit, Fixed, LookupRangeCheckConfig>
+pub struct SinsemillaChip<Hash, Commit, Fixed, Lookup>
 where
     Hash: HashDomains<pallas::Affine>,
     Fixed: FixedPoints<pallas::Affine>,
     Commit: CommitDomains<pallas::Affine, Fixed, Hash>,
-    LookupRangeCheckConfig: DefaultLookupRangeCheck,
+    Lookup: DefaultLookupRangeCheck,
 {
-    config: SinsemillaConfig<Hash, Commit, Fixed, LookupRangeCheckConfig>,
+    config: SinsemillaConfig<Hash, Commit, Fixed, Lookup>,
 }
 
 impl<Hash, Commit, Fixed, LookupRangeCheckConfig> Chip<pallas::Base>
diff --git a/halo2_gadgets/src/sinsemilla/merkle/chip.rs b/halo2_gadgets/src/sinsemilla/merkle/chip.rs
index dc7fb3f6f8..bafd64fd10 100644
--- a/halo2_gadgets/src/sinsemilla/merkle/chip.rs
+++ b/halo2_gadgets/src/sinsemilla/merkle/chip.rs
@@ -11,13 +11,9 @@ use super::MerkleInstructions;
 
 use crate::{
     sinsemilla::{primitives as sinsemilla, MessagePiece},
-    utilities::{lookup_range_check::DefaultLookupRangeCheck, RangeConstrained},
+    utilities::RangeConstrained,
     {
-        ecc::FixedPoints,
-        sinsemilla::{
-            chip::{SinsemillaChip, SinsemillaConfig},
-            CommitDomains, HashDomains, SinsemillaInstructions,
-        },
+        sinsemilla::SinsemillaInstructions,
         utilities::{
             cond_swap::{CondSwapChip, CondSwapConfig, CondSwapInstructions},
             UtilitiesInstructions,
@@ -28,17 +24,15 @@ use group::ff::PrimeField;
 
 /// Configuration for the `MerkleChip` implementation.
 #[derive(Clone, Debug, PartialEq, Eq)]
-pub struct MerkleConfig<Hash, Commit, Fixed, LookupRangeCheckConfig>
+pub struct MerkleConfig<SinsemillaChip>
 where
-    Hash: HashDomains<pallas::Affine>,
-    Fixed: FixedPoints<pallas::Affine>,
-    Commit: CommitDomains<pallas::Affine, Fixed, Hash>,
-    LookupRangeCheckConfig: DefaultLookupRangeCheck,
+    SinsemillaChip: Chip<pallas::Base>
+        + SinsemillaInstructions<pallas::Affine, { sinsemilla::K }, { sinsemilla::C }>,
 {
     advices: [Column<Advice>; 5],
     q_decompose: Selector,
     pub(crate) cond_swap_config: CondSwapConfig,
-    pub(crate) sinsemilla_config: SinsemillaConfig<Hash, Commit, Fixed, LookupRangeCheckConfig>,
+    sinsemilla_chip: SinsemillaChip,
 }
 
 /// Chip implementing `MerkleInstructions`.
@@ -52,25 +46,20 @@ where
 /// This chip does **NOT** constrain `left⋆` and `right⋆` to be canonical encodings of
 /// `left` and `right`.
 #[derive(Clone, Debug, PartialEq, Eq)]
-pub struct MerkleChip<Hash, Commit, Fixed, LookupRangeCheckConfig>
+pub struct MerkleChip<SinsemillaChip>
 where
-    Hash: HashDomains<pallas::Affine>,
-    Fixed: FixedPoints<pallas::Affine>,
-    Commit: CommitDomains<pallas::Affine, Fixed, Hash>,
-    LookupRangeCheckConfig: DefaultLookupRangeCheck,
+    SinsemillaChip: Chip<pallas::Base>
+        + SinsemillaInstructions<pallas::Affine, { sinsemilla::K }, { sinsemilla::C }>,
 {
-    config: MerkleConfig<Hash, Commit, Fixed, LookupRangeCheckConfig>,
+    config: MerkleConfig<SinsemillaChip>,
 }
 
-impl<Hash, Commit, Fixed, LookupRangeCheckConfig> Chip<pallas::Base>
-    for MerkleChip<Hash, Commit, Fixed, LookupRangeCheckConfig>
+impl<SinsemillaChip> Chip<pallas::Base> for MerkleChip<SinsemillaChip>
 where
-    Hash: HashDomains<pallas::Affine>,
-    Fixed: FixedPoints<pallas::Affine>,
-    Commit: CommitDomains<pallas::Affine, Fixed, Hash>,
-    LookupRangeCheckConfig: DefaultLookupRangeCheck,
+    SinsemillaChip: Chip<pallas::Base>
+        + SinsemillaInstructions<pallas::Affine, { sinsemilla::K }, { sinsemilla::C }>,
 {
-    type Config = MerkleConfig<Hash, Commit, Fixed, LookupRangeCheckConfig>;
+    type Config = MerkleConfig<SinsemillaChip>;
     type Loaded = ();
 
     fn config(&self) -> &Self::Config {
@@ -82,20 +71,18 @@ where
     }
 }
 
-impl<Hash, Commit, F, LookupRangeCheckConfig> MerkleChip<Hash, Commit, F, LookupRangeCheckConfig>
+impl<SinsemillaChip> MerkleChip<SinsemillaChip>
 where
-    Hash: HashDomains<pallas::Affine>,
-    F: FixedPoints<pallas::Affine>,
-    Commit: CommitDomains<pallas::Affine, F, Hash>,
-    LookupRangeCheckConfig: DefaultLookupRangeCheck,
+    SinsemillaChip: Chip<pallas::Base>
+        + SinsemillaInstructions<pallas::Affine, { sinsemilla::K }, { sinsemilla::C }>,
 {
     /// Configures the [`MerkleChip`].
     pub fn configure(
         meta: &mut ConstraintSystem<pallas::Base>,
-        sinsemilla_config: SinsemillaConfig<Hash, Commit, F, LookupRangeCheckConfig>,
-    ) -> MerkleConfig<Hash, Commit, F, LookupRangeCheckConfig> {
+        sinsemilla_chip: SinsemillaChip,
+    ) -> MerkleConfig<SinsemillaChip> {
         // All five advice columns are equality-enabled by SinsemillaConfig.
-        let advices = sinsemilla_config.advices();
+        let advices = sinsemilla_chip.config().advices();
         let cond_swap_config = CondSwapChip::configure(meta, advices);
 
         // This selector enables the decomposition gate.
@@ -191,24 +178,22 @@ where
             advices,
             q_decompose,
             cond_swap_config,
-            sinsemilla_config,
+            sinsemilla_chip,
         }
     }
 
     /// Constructs a [`MerkleChip`] given a [`MerkleConfig`].
-    pub fn construct(config: MerkleConfig<Hash, Commit, F, LookupRangeCheckConfig>) -> Self {
+    pub fn construct(config: MerkleConfig<SinsemillaChip>) -> Self {
         MerkleChip { config }
     }
 }
 
-impl<Hash, Commit, F, LookupRangeCheckConfig, const MERKLE_DEPTH: usize>
+impl<SinsemillaChip, const MERKLE_DEPTH: usize>
     MerkleInstructions<pallas::Affine, MERKLE_DEPTH, { sinsemilla::K }, { sinsemilla::C }>
-    for MerkleChip<Hash, Commit, F, LookupRangeCheckConfig>
+    for MerkleChip<SinsemillaChip>
 where
-    Hash: HashDomains<pallas::Affine> + Eq,
-    F: FixedPoints<pallas::Affine>,
-    Commit: CommitDomains<pallas::Affine, F, Hash> + Eq,
-    LookupRangeCheckConfig: DefaultLookupRangeCheck,
+    SinsemillaChip: Chip<pallas::Base>
+        + SinsemillaInstructions<pallas::Affine, { sinsemilla::K }, { sinsemilla::C }>,
 {
     #[allow(non_snake_case)]
     fn hash_layer(
@@ -421,24 +406,18 @@ where
     }
 }
 
-impl<Hash, Commit, F, LookupRangeCheckConfig> UtilitiesInstructions<pallas::Base>
-    for MerkleChip<Hash, Commit, F, LookupRangeCheckConfig>
+impl<SinsemillaChip> UtilitiesInstructions<pallas::Base> for MerkleChip<SinsemillaChip>
 where
-    Hash: HashDomains<pallas::Affine>,
-    F: FixedPoints<pallas::Affine>,
-    Commit: CommitDomains<pallas::Affine, F, Hash>,
-    LookupRangeCheckConfig: DefaultLookupRangeCheck,
+    SinsemillaChip: Chip<pallas::Base>
+        + SinsemillaInstructions<pallas::Affine, { sinsemilla::K }, { sinsemilla::C }>,
 {
     type Var = AssignedCell<pallas::Base, pallas::Base>;
 }
 
-impl<Hash, Commit, F, LookupRangeCheckConfig> CondSwapInstructions<pallas::Base>
-    for MerkleChip<Hash, Commit, F, LookupRangeCheckConfig>
+impl<SinsemillaChip> CondSwapInstructions<pallas::Base> for MerkleChip<SinsemillaChip>
 where
-    Hash: HashDomains<pallas::Affine>,
-    F: FixedPoints<pallas::Affine>,
-    Commit: CommitDomains<pallas::Affine, F, Hash>,
-    LookupRangeCheckConfig: DefaultLookupRangeCheck,
+    SinsemillaChip: Chip<pallas::Base>
+        + SinsemillaInstructions<pallas::Affine, { sinsemilla::K }, { sinsemilla::C }>,
 {
     #[allow(clippy::type_complexity)]
     fn swap(
@@ -453,71 +432,61 @@ where
     }
 }
 
-impl<Hash, Commit, F, LookupRangeCheckConfig>
-    SinsemillaInstructions<pallas::Affine, { sinsemilla::K }, { sinsemilla::C }>
-    for MerkleChip<Hash, Commit, F, LookupRangeCheckConfig>
+// FIXME: do we need to constraint SinsemillaChipt with Chip<pallas::Base>?
+impl<SinsemillaChip> SinsemillaInstructions<pallas::Affine, { sinsemilla::K }, { sinsemilla::C }>
+    for MerkleChip<SinsemillaChip>
 where
-    Hash: HashDomains<pallas::Affine>,
-    F: FixedPoints<pallas::Affine>,
-    Commit: CommitDomains<pallas::Affine, F, Hash>,
-    LookupRangeCheckConfig: DefaultLookupRangeCheck,
+    SinsemillaChip: Chip<pallas::Base>
+        + SinsemillaInstructions<pallas::Affine, { sinsemilla::K }, { sinsemilla::C }>,
 {
-    type CellValue =
-        <SinsemillaChip<Hash, Commit, F, LookupRangeCheckConfig> as SinsemillaInstructions<
-            pallas::Affine,
-            { sinsemilla::K },
-            { sinsemilla::C },
-        >>::CellValue;
-
-    type Message =
-        <SinsemillaChip<Hash, Commit, F, LookupRangeCheckConfig> as SinsemillaInstructions<
-            pallas::Affine,
-            { sinsemilla::K },
-            { sinsemilla::C },
-        >>::Message;
-    type MessagePiece =
-        <SinsemillaChip<Hash, Commit, F, LookupRangeCheckConfig> as SinsemillaInstructions<
-            pallas::Affine,
-            { sinsemilla::K },
-            { sinsemilla::C },
-        >>::MessagePiece;
-    type RunningSum =
-        <SinsemillaChip<Hash, Commit, F, LookupRangeCheckConfig> as SinsemillaInstructions<
-            pallas::Affine,
-            { sinsemilla::K },
-            { sinsemilla::C },
-        >>::RunningSum;
-
-    type X = <SinsemillaChip<Hash, Commit, F, LookupRangeCheckConfig> as SinsemillaInstructions<
+    type CellValue = <SinsemillaChip as SinsemillaInstructions<
+        pallas::Affine,
+        { sinsemilla::K },
+        { sinsemilla::C },
+    >>::CellValue;
+
+    type Message = <SinsemillaChip as SinsemillaInstructions<
+        pallas::Affine,
+        { sinsemilla::K },
+        { sinsemilla::C },
+    >>::Message;
+    type MessagePiece = <SinsemillaChip as SinsemillaInstructions<
+        pallas::Affine,
+        { sinsemilla::K },
+        { sinsemilla::C },
+    >>::MessagePiece;
+    type RunningSum = <SinsemillaChip as SinsemillaInstructions<
+        pallas::Affine,
+        { sinsemilla::K },
+        { sinsemilla::C },
+    >>::RunningSum;
+
+    type X = <SinsemillaChip as SinsemillaInstructions<
         pallas::Affine,
         { sinsemilla::K },
         { sinsemilla::C },
     >>::X;
-    type NonIdentityPoint =
-        <SinsemillaChip<Hash, Commit, F, LookupRangeCheckConfig> as SinsemillaInstructions<
-            pallas::Affine,
-            { sinsemilla::K },
-            { sinsemilla::C },
-        >>::NonIdentityPoint;
-    type FixedPoints =
-        <SinsemillaChip<Hash, Commit, F, LookupRangeCheckConfig> as SinsemillaInstructions<
-            pallas::Affine,
-            { sinsemilla::K },
-            { sinsemilla::C },
-        >>::FixedPoints;
-
-    type HashDomains =
-        <SinsemillaChip<Hash, Commit, F, LookupRangeCheckConfig> as SinsemillaInstructions<
-            pallas::Affine,
-            { sinsemilla::K },
-            { sinsemilla::C },
-        >>::HashDomains;
-    type CommitDomains =
-        <SinsemillaChip<Hash, Commit, F, LookupRangeCheckConfig> as SinsemillaInstructions<
-            pallas::Affine,
-            { sinsemilla::K },
-            { sinsemilla::C },
-        >>::CommitDomains;
+    type NonIdentityPoint = <SinsemillaChip as SinsemillaInstructions<
+        pallas::Affine,
+        { sinsemilla::K },
+        { sinsemilla::C },
+    >>::NonIdentityPoint;
+    type FixedPoints = <SinsemillaChip as SinsemillaInstructions<
+        pallas::Affine,
+        { sinsemilla::K },
+        { sinsemilla::C },
+    >>::FixedPoints;
+
+    type HashDomains = <SinsemillaChip as SinsemillaInstructions<
+        pallas::Affine,
+        { sinsemilla::K },
+        { sinsemilla::C },
+    >>::HashDomains;
+    type CommitDomains = <SinsemillaChip as SinsemillaInstructions<
+        pallas::Affine,
+        { sinsemilla::K },
+        { sinsemilla::C },
+    >>::CommitDomains;
 
     fn witness_message_piece(
         &self,
@@ -526,8 +495,8 @@ where
         num_words: usize,
     ) -> Result<Self::MessagePiece, Error> {
         let config = self.config().sinsemilla_config.clone();
-        let chip = SinsemillaChip::<Hash, Commit, F, LookupRangeCheckConfig>::construct(config);
-        chip.witness_message_piece(layouter, value, num_words)
+        self.sinsemilla_chip
+            .witness_message_piece(layouter, value, num_words)
     }
 
     #[allow(non_snake_case)]
@@ -539,11 +508,10 @@ where
         message: Self::Message,
     ) -> Result<(Self::NonIdentityPoint, Vec<Vec<Self::CellValue>>), Error> {
         let config = self.config().sinsemilla_config.clone();
-        let chip = SinsemillaChip::<Hash, Commit, F, LookupRangeCheckConfig>::construct(config);
-        chip.hash_to_point(layouter, Q, message)
+        self.sinsemilla_chip.hash_to_point(layouter, Q, message)
     }
 
     fn extract(point: &Self::NonIdentityPoint) -> Self::X {
-        SinsemillaChip::<Hash, Commit, F, LookupRangeCheckConfig>::extract(point)
+        SinsemillaChip::extract(point)
     }
 }
diff --git a/halo2_gadgets/src/sinsemilla_opt/merkle/chip.rs b/halo2_gadgets/src/sinsemilla_opt/merkle/chip.rs
index 14b6a41579..6f50cc999b 100644
--- a/halo2_gadgets/src/sinsemilla_opt/merkle/chip.rs
+++ b/halo2_gadgets/src/sinsemilla_opt/merkle/chip.rs
@@ -8,23 +8,16 @@ use pasta_curves::pallas;
 
 use crate::{
     sinsemilla::{merkle::chip::MerkleChip, primitives as sinsemilla},
-    sinsemilla_opt::SinsemillaInstructionsOptimized,
-    utilities_opt::lookup_range_check::DefaultLookupRangeCheckConfigOptimized,
     {
-        ecc::FixedPoints,
-        sinsemilla::{CommitDomains, HashDomains},
-        sinsemilla_opt::chip::SinsemillaChipOptimized,
-        utilities::cond_swap::CondSwapChip,
+        sinsemilla::SinsemillaInstructions, utilities::cond_swap::CondSwapChip,
         utilities_opt::cond_swap::CondSwapInstructionsOptimized,
     },
 };
 
-impl<Hash, Commit, F> CondSwapInstructionsOptimized<pallas::Base>
-    for MerkleChip<Hash, Commit, F, DefaultLookupRangeCheckConfigOptimized>
+impl<SinsemillaChip> CondSwapInstructionsOptimized<pallas::Base> for MerkleChip<SinsemillaChip>
 where
-    Hash: HashDomains<pallas::Affine>,
-    F: FixedPoints<pallas::Affine>,
-    Commit: CommitDomains<pallas::Affine, F, Hash>,
+    SinsemillaChip: Chip<pallas::Base>
+        + SinsemillaInstructions<pallas::Affine, { sinsemilla::K }, { sinsemilla::C }>,
 {
     fn mux(
         &self,
@@ -39,13 +32,14 @@ where
     }
 }
 
-impl<Hash, Commit, F>
+// FIXME: uncomment and implement this properly
+/*
+impl<SinsemillaChip>
     SinsemillaInstructionsOptimized<pallas::Affine, { sinsemilla::K }, { sinsemilla::C }>
-    for MerkleChip<Hash, Commit, F, DefaultLookupRangeCheckConfigOptimized>
+    for MerkleChip<SinsemillaChip>
 where
-    Hash: HashDomains<pallas::Affine>,
-    F: FixedPoints<pallas::Affine>,
-    Commit: CommitDomains<pallas::Affine, F, Hash>,
+    SinsemillaChip: Chip<pallas::Base>
+        + SinsemillaInstructions<pallas::Affine, { sinsemilla::K }, { sinsemilla::C }>,
 {
     #[allow(non_snake_case)]
     #[allow(clippy::type_complexity)]
@@ -60,3 +54,4 @@ where
         chip.hash_to_point_with_private_init(layouter, Q, message)
     }
 }
+*/
diff --git a/halo2_gadgets/src/utilities/lookup_range_check.rs b/halo2_gadgets/src/utilities/lookup_range_check.rs
index 09369c04f1..e938d1cf3a 100644
--- a/halo2_gadgets/src/utilities/lookup_range_check.rs
+++ b/halo2_gadgets/src/utilities/lookup_range_check.rs
@@ -426,3 +426,6 @@ pub trait DefaultLookupRangeCheck:
 }
 
 impl DefaultLookupRangeCheck for LookupRangeCheckConfig<pallas::Base, { sinsemilla::K }> {}
+
+pub(crate) type DefaultLookupRangeCheckConfig =
+    LookupRangeCheckConfig<pallas::Base, { sinsemilla::K }>;
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
deleted file mode 100644
index 948d27daa4..0000000000
--- a/rust-toolchain.toml
+++ /dev/null
@@ -1,2 +0,0 @@
-[toolchain]
-channel = "1.60.0"