either trough his Discord Channel, or directly trough Patreon would be the save bet, although I guess he gets pretty spammed, but someone of his team maybe answers you
I'd say the most recent version is the best version. The art reworks, in my opinion, have made characters look better. A few scenes have been removed/modified, but the overall package is significantly superior to earlier versions. Only if you're curious, check out previous posts as some people have posted how Ain used to look in different versions.
I'd suggest trying the .01 version to see how it all started and at least .04 to see the original Kyra rescue and midnight market scene. I, personally, like the original scenes.