diff --git a/acegen/priors/custom_model.ckpt b/acegen/priors/custom_model.ckpt
index 5d60c9fd..35a00b00 100644
Binary files a/acegen/priors/custom_model.ckpt and b/acegen/priors/custom_model.ckpt differ
diff --git a/scripts/a2c/a2c.py b/scripts/a2c/a2c.py
index 1223d465..024186d4 100644
--- a/scripts/a2c/a2c.py
+++ b/scripts/a2c/a2c.py
@@ -13,7 +13,7 @@
 import tqdm
 import yaml
 
-from acegen.models import adapt_state_dict, models
+from acegen.models import adapt_state_dict, models, register_model
 from acegen.rl_env import generate_complete_smiles, SMILESEnv
 from acegen.scoring_functions import custom_scoring_functions, Task
 from acegen.vocabulary import SMILESVocabulary
@@ -125,17 +125,19 @@ def run_a2c(cfg, task):
     )
 
     # Get model and vocabulary checkpoints
-    if cfg.model in models:
-        (
-            create_actor,
-            create_critic,
-            create_shared,
-            voc_path,
-            ckpt_path,
-            tokenizer,
-        ) = models[cfg.model]
+    if cfg.model not in models and cfg.model_factory is not None:
+        register_model(cfg.model, cfg.model_factory)
     else:
-        raise ValueError(f"Unknown model type: {cfg.model}")
+        raise ValueError(f"Model {cfg.model} not found. For custom models, create and register a model factory.")
+
+    (
+        create_actor,
+        create_critic,
+        create_shared,
+        voc_path,
+        ckpt_path,
+        tokenizer
+    ) = models[cfg.model](cfg)
 
     # Create vocabulary
     ####################################################################################################################
@@ -158,7 +160,9 @@ def run_a2c(cfg, task):
         critic_training, critic_inference = create_critic(len(vocabulary))
 
     # Load pretrained weights
-    ckpt = torch.load(ckpt_path)
+    ckpt_path = cfg.get("model_weights", ckpt_path)
+    ckpt = torch.load(ckpt_path, map_location=device)
+
     actor_inference.load_state_dict(
         adapt_state_dict(ckpt, actor_inference.state_dict())
     )
diff --git a/scripts/ahc/ahc.py b/scripts/ahc/ahc.py
index d2b3b0b3..ee15f378 100644
--- a/scripts/ahc/ahc.py
+++ b/scripts/ahc/ahc.py
@@ -14,7 +14,7 @@
 import tqdm
 import yaml
 
-from acegen.models import adapt_state_dict, models
+from acegen.models import adapt_state_dict, models, register_model
 from acegen.rl_env import generate_complete_smiles, SMILESEnv
 from acegen.scoring_functions import custom_scoring_functions, Task
 from acegen.vocabulary import SMILESVocabulary
@@ -127,10 +127,12 @@ def run_ahc(cfg, task):
     )
 
     # Get model and vocabulary checkpoints
-    if cfg.model in models:
-        create_actor, _, _, voc_path, ckpt_path, tokenizer = models[cfg.model]
+    if cfg.model not in models and cfg.model_factory is not None:
+        register_model(cfg.model, cfg.model_factory)
     else:
-        raise ValueError(f"Unknown model type: {cfg.model}")
+        raise ValueError(f"Model {cfg.model} not found. For custom models, create and register a model factory.")
+
+    create_actor, _, _, voc_path, ckpt_path, tokenizer = models[cfg.model](cfg)
 
     # Create vocabulary
     ####################################################################################################################
@@ -140,6 +142,7 @@ def run_ahc(cfg, task):
     # Create models
     ####################################################################################################################
 
+    ckpt_path = cfg.get("model_weights", ckpt_path)
     ckpt = torch.load(ckpt_path)
 
     actor_training, actor_inference = create_actor(vocabulary_size=len(vocabulary))
diff --git a/scripts/ppo/ppo.py b/scripts/ppo/ppo.py
index 18c67ec8..9a96dd7c 100644
--- a/scripts/ppo/ppo.py
+++ b/scripts/ppo/ppo.py
@@ -13,7 +13,7 @@
 import tqdm
 import yaml
 
-from acegen.models import adapt_state_dict, models
+from acegen.models import adapt_state_dict, models, register_model
 from acegen.rl_env import generate_complete_smiles, SMILESEnv
 from acegen.scoring_functions import custom_scoring_functions, Task
 from acegen.vocabulary import SMILESVocabulary
@@ -128,17 +128,20 @@ def run_ppo(cfg, task):
     )
 
     # Get model and vocabulary checkpoints
-    if cfg.model in models:
-        (
-            create_actor,
-            create_critic,
-            create_shared,
-            voc_path,
-            ckpt_path,
-            tokenizer,
-        ) = models[cfg.model](cfg)
+    if cfg.model not in models and cfg.model_factory is not None:
+        register_model(cfg.model, cfg.model_factory)
     else:
-        raise ValueError(f"Unknown model type: {cfg.model}")
+        raise ValueError(f"Model {cfg.model} not found. For custom models, create and register a model factory.")
+
+    (
+        create_actor,
+        create_critic,
+        create_shared,
+        voc_path,
+        ckpt_path,
+        tokenizer
+    ) = models[cfg.model](cfg)
+
 
     # Create vocabulary
     ####################################################################################################################
diff --git a/scripts/reinforce/reinforce.py b/scripts/reinforce/reinforce.py
index 8ad5b8ee..cee13f26 100644
--- a/scripts/reinforce/reinforce.py
+++ b/scripts/reinforce/reinforce.py
@@ -14,7 +14,7 @@
 import tqdm
 import yaml
 
-from acegen.models import adapt_state_dict, models
+from acegen.models import adapt_state_dict, models, register_model
 from acegen.rl_env import generate_complete_smiles, SMILESEnv
 from acegen.scoring_functions import custom_scoring_functions, Task
 from acegen.vocabulary import SMILESVocabulary
@@ -127,10 +127,12 @@ def run_reinforce(cfg, task):
     )
 
     # Get model and vocabulary checkpoints
-    if cfg.model in models:
-        create_actor, _, _, voc_path, ckpt_path, tokenizer = models[cfg.model]
+    if cfg.model not in models and cfg.model_factory is not None:
+        register_model(cfg.model, cfg.model_factory)
     else:
-        raise ValueError(f"Unknown model type: {cfg.model}")
+        raise ValueError(f"Model {cfg.model} not found. For custom models, create and register a model factory.")
+
+    create_actor, _, _, voc_path, ckpt_path, tokenizer = models[cfg.model](cfg)
 
     # Create vocabulary
     ####################################################################################################################
@@ -140,6 +142,7 @@ def run_reinforce(cfg, task):
     # Create models
     ####################################################################################################################
 
+    ckpt_path = cfg.get("model_weights", ckpt_path)
     ckpt = torch.load(ckpt_path)
 
     actor_training, actor_inference = create_actor(vocabulary_size=len(vocabulary))
diff --git a/scripts/reinvent/reinvent.py b/scripts/reinvent/reinvent.py
index f477a7d6..f189001d 100644
--- a/scripts/reinvent/reinvent.py
+++ b/scripts/reinvent/reinvent.py
@@ -13,7 +13,6 @@
 import torch
 import tqdm
 import yaml
-from importlib import import_module
 
 from acegen.models import adapt_state_dict, models, register_model
 from acegen.rl_env import generate_complete_smiles, SMILESEnv
@@ -128,13 +127,12 @@ def run_reinvent(cfg, task):
     )
 
     # Get model and vocabulary checkpoints
-    if cfg.model in models:
-        create_actor, _, _, voc_path, ckpt_path, tokenizer = models[cfg.model](cfg)
+    if cfg.model not in models and cfg.model_factory is not None:
+        register_model(cfg.model, cfg.model_factory)
     else:
-        m, f = cfg.model_factory.rsplit('.', 1)
-        model_factory = getattr(import_module(m), f)
-        register_model(cfg.model, model_factory)
-        create_actor, _, _, voc_path, ckpt_path, tokenizer = models[cfg.model](cfg)
+        raise ValueError(f"Model {cfg.model} not found. For custom models, create and register a model factory.")
+
+    create_actor, _, _, voc_path, ckpt_path, tokenizer = models[cfg.model](cfg)
 
     # Create vocabulary
     ####################################################################################################################
@@ -144,7 +142,6 @@ def run_reinvent(cfg, task):
     # Create models
     ####################################################################################################################
 
-    #ckpt = torch.load(ckpt_path)
     ckpt_path = cfg.get("model_weights", ckpt_path)
     ckpt = torch.load(ckpt_path)