Aha. I think we agree. I originally said "C on CHERI hardware is memory safe" by which I meant "the system as a whole of (C code + CHERI hardware)" is memory safe, but you seemed to think I meant (C code) is memory safe.
I actually had thought you meant something like "the C language is memory safe when run on CHERI". If you mean that running a C program on CHERI prevents memory safety from actually being broken, then yeah, I guess we do agree. On CHERI, even if the C program alone isn't completely sound, and so attempts to violate memory safety, the attempt won't actually succeed, so memory safety won't actually be violated.