Nice work indeed. It must have taken you a while to lay that PCB.
When considering future development, my opinion is that compatibility is important but given that this is a brand new PCB, which diverges from "original" anyway, I think the door is open for a lot of decent improvements and if I were you I would not be shy of implementing them.
Obviously each person will have their own ideas about which improvements they would like to see, and from that list only some of them will be feasible. But this is a very nice project and I congratulate you on it! I will pay attention to its continued development.
Out of interest, what PCB package are you on?
