diff --git a/.cargo/config.toml b/.cargo/config.toml
index 902ceebb7cea1..4796a2c26965c 100644
--- a/.cargo/config.toml
+++ b/.cargo/config.toml
@@ -30,7 +30,4 @@ rustflags = [
   "-Aclippy::derivable_impls",           # false positives
   "-Aclippy::stable_sort_primitive",     # prefer stable sort
   "-Aclippy::extra-unused-type-parameters", # stylistic
-  "-Aclippy::let_with_type_underscore"   # used as a workaround for an infinite macro expansion loop in clippy
-                                         # specifying this as an attribute directly in the affected macro
-                                         # triggers other weird rust 1.70 bugs
 ]
diff --git a/frame/assets/src/benchmarking.rs b/frame/assets/src/benchmarking.rs
index ff20b3e187217..982edf33514cf 100644
--- a/frame/assets/src/benchmarking.rs
+++ b/frame/assets/src/benchmarking.rs
@@ -144,7 +144,7 @@ benchmarks_instance_pallet! {
 		let caller = T::CreateOrigin::ensure_origin(origin.clone(), &asset_id.into()).unwrap();
 		let caller_lookup = T::Lookup::unlookup(caller.clone());
 		T::Currency::make_free_balance_be(&caller, DepositBalanceOf::<T, I>::max_value());
-	}: _<T::RuntimeOrigin>(origin, asset_id.clone(), caller_lookup, 1u32.into())
+	}: _<T::RuntimeOrigin>(origin, asset_id, caller_lookup, 1u32.into())
 	verify {
 		assert_last_event::<T, I>(Event::Created { asset_id: asset_id.into(), creator: caller.clone(), owner: caller }.into());
 	}
diff --git a/frame/benchmarking/src/v1.rs b/frame/benchmarking/src/v1.rs
index be6dc393cbce3..acfdbce965206 100644
--- a/frame/benchmarking/src/v1.rs
+++ b/frame/benchmarking/src/v1.rs
@@ -661,7 +661,7 @@ macro_rules! benchmark_backend {
 		{ $( PRE { $( $pre_parsed:tt )* } )* }
 		{ $eval:block }
 		{
-			let $pre_id:tt : $pre_ty:ty = $pre_ex:expr;
+			let $pre_id:tt $( : $pre_ty:ty )? = $pre_ex:expr;
 			$( $rest:tt )*
 		}
 		$postcode:block
@@ -672,7 +672,7 @@ macro_rules! benchmark_backend {
 			{ $( $where_clause )* }
 			{
 				$( PRE { $( $pre_parsed )* } )*
-				PRE { $pre_id , $pre_ty , $pre_ex }
+				PRE { $pre_id , $( $pre_ty , )? $pre_ex }
 			}
 			{ $eval }
 			{ $( $rest )* }
@@ -756,39 +756,13 @@ macro_rules! benchmark_backend {
 			$postcode
 		}
 	};
-	// mutation arm to look after `let _ =`
-	(
-		{ $( $instance:ident: $instance_bound:tt )? }
-		$name:ident
-		{ $( $where_clause:tt )* }
-		{ $( $parsed:tt )* }
-		{ $eval:block }
-		{
-			let $pre_id:tt = $pre_ex:expr;
-			$( $rest:tt )*
-		}
-		$postcode:block
-	) => {
-		$crate::benchmark_backend! {
-			{ $( $instance: $instance_bound )? }
-			$name
-			{ $( $where_clause )* }
-			{ $( $parsed )* }
-			{ $eval }
-			{
-				let $pre_id : _ = $pre_ex;
-				$( $rest )*
-			}
-			$postcode
-		}
-	};
 	// actioning arm
 	(
 		{ $( $instance:ident: $instance_bound:tt )? }
 		$name:ident
 		{ $( $where_clause:tt )* }
 		{
-			$( PRE { $pre_id:tt , $pre_ty:ty , $pre_ex:expr } )*
+			$( PRE { $pre_id:tt , $( $pre_ty:ty , )? $pre_ex:expr } )*
 			$( PARAM { $param:ident , $param_from:expr , $param_to:expr , $param_instancer:expr } )*
 		}
 		{ $eval:block }
@@ -823,7 +797,7 @@ macro_rules! benchmark_backend {
 						.1;
 				)*
 				$(
-					let $pre_id : $pre_ty = $pre_ex;
+					let $pre_id $( : $pre_ty )? = $pre_ex;
 				)*
 				$( $param_instancer ; )*
 				$( $post )*
diff --git a/frame/nfts/src/benchmarking.rs b/frame/nfts/src/benchmarking.rs
index 2be115f17a474..45390bf032bd6 100644
--- a/frame/nfts/src/benchmarking.rs
+++ b/frame/nfts/src/benchmarking.rs
@@ -680,9 +680,9 @@ benchmarks_instance_pallet! {
 		let buyer_lookup = T::Lookup::unlookup(buyer.clone());
 		let price = ItemPrice::<T, I>::from(0u32);
 		let origin = SystemOrigin::Signed(seller.clone()).into();
-		Nfts::<T, I>::set_price(origin, collection, item, Some(price.clone()), Some(buyer_lookup))?;
+		Nfts::<T, I>::set_price(origin, collection, item, Some(price), Some(buyer_lookup))?;
 		T::Currency::make_free_balance_be(&buyer, DepositBalanceOf::<T, I>::max_value());
-	}: _(SystemOrigin::Signed(buyer.clone()), collection, item, price.clone())
+	}: _(SystemOrigin::Signed(buyer.clone()), collection, item, price)
 	verify {
 		assert_last_event::<T, I>(Event::ItemBought {
 			collection,