I assumed that with things like cassius coins, people now expect an imported key to be "safe to import", and future versions would try to keep it this way... I admit though it's probably better to start fresh and not take any chances... I just wanted to see if this was URGENT , or safe to do "in the next few weeks"

Yeah, but most of the developers don't like making private key fiddling "easy" because they feel (correctly, IMO) it's inherently unsafe and confusing to most users. See
here and
here.