God, this is the exact ROM hack I tried making ages ago but just stopped because I had no direction and very little patience. I just wanted to play and mess around, but I'm very happy to see someone somehow had an extremely similar idea and put pen to paper to make it happen.
It's like, everything I've ever wanted is here and now I don't have to make a whole rom hack to play what I want haha
Will the final game be compatible with older save files?
Word from the discord is yes. Colonel answered the question like 2 months ago and said there is a 95% chance they will carry over. So the answer is likely yes. But there is always the chance that those 5% kick in I guess =P