How about a more generalised collaboration system, where you just edit your files lot Cally as standard, but can kind of dial in using o collaboration - a bit l

How about a more generalised collaboration system, where you just edit your files lot Cally as standard, but can kind of dial in using o collaboration - a bit like a screen share on a call. So suddenly the people you've dialled can leave comments on your work etc, but when you cut the connection, they can't any more?