I could technically add rumble support in the course of a few minutes for rumble carts, but it wouldn't be very fine-tuned.
Hi Evan, and thank you for the reply. that sounds great! I guess I just wanted to really convey that there are some of us who really appreciate good rumble in a game, so I'm happy to hear it'll go on the list – and I'll be very much looking forward to it – both on OG hardware and the Miyoo (actually, now the RG28XX, which blows the Miyoo out the window, and is kinda the ultimate modern GB Micro! – for me anyway).
Best wish for all your projects.