chore: addressing comments

src/merkle/smt/full/mod.rs

@@ -255,9 +255,7 @@ impl Smt {
         <Self as SparseMerkleTree<SMT_DEPTH>>::compute_mutations(self, kv_pairs)
     }
 
-    /// Applies the prospective mutations computed with [`Smt::compute_mutations()`] to
-    /// this tree and returns the reverse mutation set. Applying the reverse mutation sets to the
-    /// updated tree will revert the changes.
+    /// Applies the prospective mutations computed with [`Smt::compute_mutations()`] to this tree.
     ///
     /// # Errors
     /// If `mutations` was computed on a tree with a different root than this one, returns

src/merkle/smt/mod.rs

@@ -182,6 +182,8 @@ pub(crate) trait SparseMerkleTree<const DEPTH: u8> {
     ) -> MutationSet<DEPTH, Self::Key, Self::Value>
     where
         Self: Sized + Sync,
+        Self::Key: Send + Sync,
+        Self::Value: Send + Sync,
     {
         #[cfg(feature = "concurrent")]
         {
@@ -307,12 +309,14 @@ pub(crate) trait SparseMerkleTree<const DEPTH: u8> {
     ) -> MutationSet<DEPTH, Self::Key, Self::Value>
     where
         Self: Sized + Sync,
+        Self::Key: Send + Sync,
+        Self::Value: Send + Sync,
     {
         use rayon::prelude::*;
 
         // Collect and sort key-value pairs by their corresponding leaf index
         let mut sorted_kv_pairs: Vec<_> = kv_pairs.into_iter().collect();
-        sorted_kv_pairs.sort_unstable_by_key(|(key, _)| Self::key_to_leaf_index(key).value());
+        sorted_kv_pairs.par_sort_unstable_by_key(|(key, _)| Self::key_to_leaf_index(key).value());
 
         // Convert sorted pairs into mutated leaves and capture any new pairs
         let (mut subtree_leaves, new_pairs) =