diff --git a/vpr/src/pack/re_cluster_util.cpp b/vpr/src/pack/re_cluster_util.cpp
index d8e8271c028..68e04e4b888 100644
--- a/vpr/src/pack/re_cluster_util.cpp
+++ b/vpr/src/pack/re_cluster_util.cpp
@@ -129,7 +129,8 @@ bool start_new_cluster_for_mol(t_pack_molecule* molecule,
                                t_clustering_data& clustering_data,
                                t_lb_router_data** router_data,
                                PartitionRegion& temp_cluster_pr,
-                               NocGroupId& temp_cluster_noc_grp_id) {
+                               NocGroupId& temp_cluster_noc_grp_id,
+                               enum e_detailed_routing_stages detailed_routing_stage) {
     auto& atom_ctx = g_vpr_ctx.atom();
     auto& floorplanning_ctx = g_vpr_ctx.mutable_floorplanning();
     auto& helper_ctx = g_vpr_ctx.mutable_cl_helper();
@@ -164,7 +165,7 @@ bool start_new_cluster_for_mol(t_pack_molecule* molecule,
                                     helper_ctx.num_models,
                                     helper_ctx.max_cluster_size,
                                     clb_index,
-                                    E_DETAILED_ROUTE_FOR_EACH_ATOM,
+                                    detailed_routing_stage,
                                     *router_data,
                                     0,
                                     enable_pin_feasibility_filter,
@@ -213,7 +214,9 @@ bool pack_mol_in_existing_cluster(t_pack_molecule* molecule,
                                   bool during_packing,
                                   t_clustering_data& clustering_data,
                                   t_lb_router_data*& router_data,
+                                  enum e_detailed_routing_stages detailed_routing_stage,
                                   bool enable_pin_feasibility_filter) {
+
     auto& helper_ctx = g_vpr_ctx.mutable_cl_helper();
     auto& cluster_ctx = g_vpr_ctx.mutable_clustering();
 
@@ -239,7 +242,7 @@ bool pack_mol_in_existing_cluster(t_pack_molecule* molecule,
                                     helper_ctx.num_models,
                                     helper_ctx.max_cluster_size,
                                     new_clb,
-                                    E_DETAILED_ROUTE_FOR_EACH_ATOM,
+                                    detailed_routing_stage,
                                     router_data,
                                     0,
                                     enable_pin_feasibility_filter,
diff --git a/vpr/src/pack/re_cluster_util.h b/vpr/src/pack/re_cluster_util.h
index 722f725180c..78606f51fce 100644
--- a/vpr/src/pack/re_cluster_util.h
+++ b/vpr/src/pack/re_cluster_util.h
@@ -72,11 +72,18 @@ void remove_mol_from_cluster(const t_pack_molecule* molecule,
  * @param mode: the mode of the new cluster
  * @param clb_index: the cluster block Id of the newly created cluster block
  * @param during_packing: true if this function is called during packing, false if it is called during placement
- * @param clustering_data: A data structure containing helper data for the clustering process 
+ * @param clustering_data: A data structure containing helper data for the clustering process
  *                          (is updated if this function is called during packing, especially intra_lb_routing data member).
  * @param router_data: returns the intra logic block router data.
  * @param temp_cluster_pr: returns the partition region of the new cluster.
  * @param temp_cluster_noc_grp_id returns the NoC group ID of the new cluster
+ * @param detailed_routing_stage: options are E_DETAILED_ROUTE_FOR_EACH_ATOM (default) and E_DETAILED_ROUTE_AT_END_ONLY.
+ *                                This argument specifies whether or not to run an intra-cluster routing-based legality
+ *                                check after adding the molecule to the cluster; default is the more conservative option.
+ *                                This argument is passed down to try_pack_mol; if E_DETAILED_ROUTE_AT_END_ONLY is passed,
+ *                                the function does not run a detailed intra-cluster routing-based legality check.
+ *                                If many molecules will be added to a cluster, this option enables use of a single
+ *                                routing check on the completed cluster (vs many incremental checks).
  */
 bool start_new_cluster_for_mol(t_pack_molecule* molecule,
                                const t_logical_block_type_ptr& type,
@@ -89,7 +96,8 @@ bool start_new_cluster_for_mol(t_pack_molecule* molecule,
                                t_clustering_data& clustering_data,
                                t_lb_router_data** router_data,
                                PartitionRegion& temp_cluster_pr,
-                               NocGroupId& temp_cluster_noc_grp_id);
+                               NocGroupId& temp_cluster_noc_grp_id,
+                               enum e_detailed_routing_stages detailed_routing_stage = E_DETAILED_ROUTE_FOR_EACH_ATOM);
 
 /**
  * @brief A function that packs a molecule into an existing cluster
@@ -101,6 +109,14 @@ bool start_new_cluster_for_mol(t_pack_molecule* molecule,
  * @param clustering_data: A data structure containing helper data for the clustering process
  *                          (is updated if this function is called during packing, especially intra_lb_routing data member).
  * @param router_data: returns the intra logic block router data.
+ * @param temp_cluster_noc_grp_id returns the NoC group ID of the new cluster
+ * @param detailed_routing_stage: options are E_DETAILED_ROUTE_FOR_EACH_ATOM (default) and E_DETAILED_ROUTE_AT_END_ONLY.
+ *                                This argument specifies whether or not to run an intra-cluster routing-based legality
+ *                                check after adding the molecule to the cluster; default is the more conservative option.
+ *                                This argument is passed down to try_pack_mol; if E_DETAILED_ROUTE_AT_END_ONLY is passed,
+ *                                the function does not run a detailed intra-cluster routing-based legality check.
+ *                                If many molecules will be added to a cluster, this option enables use of a single
+ *                                routing check on the completed cluster (vs many incremental checks).
  * @param enable_pin_feasibility_filter: do a pin couting based legality check (before or in place of intra-cluster routing check).
  */
 bool pack_mol_in_existing_cluster(t_pack_molecule* molecule,
@@ -110,6 +126,7 @@ bool pack_mol_in_existing_cluster(t_pack_molecule* molecule,
                                   bool during_packing,
                                   t_clustering_data& clustering_data,
                                   t_lb_router_data*& router_data,
+                                  enum e_detailed_routing_stages detailed_routing_stage = E_DETAILED_ROUTE_FOR_EACH_ATOM,
                                   bool enable_pin_feasibility_filter = true);
 
 /**