Update - I've been in contact with the product developer regarding your question of AGA support, this was the response : AGA is one of the funding goals, but it's quite demanding, so we cannot promise anything yet . So there you have it!
What. They're using UAE4All, they can just copy-paste a bit of source from UAE4All2 which supports AGA emulation and bam, there you go.
This sounds like a big scam. They want money to "implement" something which is ALREADY out there?