You can't (or more like, should not) use the save file of beta 3.1 with beta 4.0.Excellent, also when the new beta does come out will I need to patch a clean copy of silver or can I just patch over 3.1, also regardless of that will I be able to use my saves from 3.1 or will I have to start over?
There are so many differences between those two versions that there are certainly bugs there, probably even game breaking ones.
Beta 4 will come when it's ready. I'll be informing about the date when the time is right. Until then, I'll be working on it on my own pace.
Yet in fact, I think I can make it in June. But that's all I'm gonna say about it.