I'm not too knowledgeable on the subject, but as far as I know, all (I believe mizu) honyaki are monosteel. All monosteels are not honyaki.
Honyaki will have a hamon as it has been differentially hardened. Suisin Inox Honyaki is not differentially hardened.
They seem to be built for pro use. Very hard edges that last but have a reputation as being fairly difficult to sharpen in relation to a monosteel blade of the same steel. Likely even more difficult to thin.
I owned one in V2 and didn't think it too difficult to sharpen, but never thinned it.