Moving the imported coins to a Z address happens automatically when you confirm the sweep dialog (maybe there was no such dialog in 1.0.0)
Then don't do this, ie do not use their wallet
Maybe you got me wrong. I'm fine with this, because I wanted to move them to a Z address anyway. Still it should be mentioned that it's mandatory (is it with cli, too?). Alternatively this necessity should be removed. Apart of that AFAIK there's no other BTCP wallet that supports (importing from?) Z addresses yet.