Jason so kindly opens a whole new kettle of fish. Jnats
You can add 2 good quality Jnats as finishing stones. Id get one to convert the synthetic scratch pattern to a jnat scratch pattern , then another to finish on.
Say take the synthetics to 8k. Use a Yaginoshima Asagi to convert the scratch pattern. Ten finish on an Ozuku Asagi , Nakayama Asagi or Nakayama Iromono.