It's been awhile, but I'm about 99.9% certain that all of the DOS cards were full-screen only.

Most of them required the hydra cable, to which you connected to your main video out and your monitor; so it would blank the Mac side while the Windows side was showing. (I think one of the all-in-ones allowed internal display switching via an internal cable.)

Filesystems would have to be shared via network, as VPC uses a different virtual hard drive than PC Setup. Clipboards should share, though, since both sync with the Mac clipboard.