In your opinion, did the writing of the VM start closer to 1412 or closer to 1440?

[Koen G]

These three later datings are quite independent and so it is coincidental that they happen to be later.

Yeah, that might certainly be the case. It just struck me that I couldn't think of anyone who needed it to be, say, 1402, but several who would prefer a date in the 1440's. As you say, people's reasons for wanting a relatively late date are varied, so there is probably nothing intrinsic about the MS that prompts this. If anything, it may have to do with the changing times, perhaps more interesting figures becoming known by name, alchemy further developing etc.