Those random changes sound really frustrating. In 3.4 that happens to the project file all the time it seems.
I forgot about the .blend importer. That'll be nice to have.
A cache scene is an interesting idea. Ik in the current RCs of 3.5 you have to turn on the uber shader. I don't know if that's the case in 4.0.
Good to hear you enjoyed 4 though. I look forward to getting over to it one day.