Exactly. :)

Why not have two parallel tracks? V4.x betas for bug fixes for V4 users and V5 betas for people who want to test new functionality? Source code versioning can easily handle such an arrangement and ensure that problems in one are fixed in the other, and vice versa. It will allow bug fixes to get to V4 users quicker.

I assume that if someone uses V5 beta then they lose access to that when the beta is over and therefore lose access to the V4 bugfixes in it?

Andy