Thanks for the answer.
I have currently an identical MC11.0 database on three PCs and I reflect any changes to all of them. I started the main database with MJ8 over three years ago and I have carried it over to each new MC version. It includes all statistics, playlists, smartlists and tags for thousands of video, document, cue, etc files that cannot contain physical tags.
It takes a lot of bravery to update the whole system. At least I would have to be reasonable sure that the new feature set is suitable for my needs.
For example, lets assume that I feel quite satisfied with the features in the current build and upgrade all the PCs and continue making changes with MC11.1. It would be OK unless a new feature change breaks something that I really need. I might be able to get that fixed, but it's also possible that the needed fixes cannot be done because they don't fit in the other plans. Anyway fixing the problem might take a long time.
On the other hand I would like to continue participating the development process. Last time it went smoothly because it was possible to have the versions 10 and 11.0 installed at the same time. During the first six or seven months I made the library changes with MC10 and used MC11 only for testing.
Is it difficult to separate the 11.0 and 11.1 registry entries? That would make possible to have both versions installed.