How late is "as late as possible"? I'm going to have a bunch of stuff to commit in a couple of weeks. This is why delaying branching is a headache for developers ... I personally use CVS as a sort of backup mechanism for my OpenACS work - I check in work regularly whenever I reach logical points in the development process where my work is internally consistent.
I'll say again what I've said before ... closing the repository to check-ins is a different style of working than I've seen elsewhere.