Even worse than the staining of the wood, CA is so thin that it wicks
a lot further into the wood than the crack, and effectively seals the
wood and prevents it from taking finish, stain or anything else

I haven't as yet ever used stain on turnings so I can't comment, but I haven't
had probems with oil varnish mixes adhereing to areas that I've hit with CA,
either in cases where I sealed before application or not (the latter for woods
that the CA did not discolor.) May I ask what finish(es) you have observed
this with??

Kip Powers
Rogers, AR