I need your advice, yo.

About a quarter to a third of the way through first draft. Beginning to notice where things have gone wrong. Nothing that interferes with the structure of the book. But voices of characters not sounding right - that kind of malarkey. Question is this: go back and tinker, on basis that getting it right now will stand me in good stead for later? Or push on through, on basis that I’m going to be rewriting the lot anyway?

Thanks, yo.