To get this sorted... I powered it up and kept swapping the USB cable inputs until it registered correctly in a retroach based emulator (I used Atari2600). Once it set correctly, I checked it in Daphne, JzIntv and DosBox. Seems to be holding and working good.
Go figure... swapping the cables with the power ON did it.
Thanks for all your help again! Pass this info on to anyone that has a similar problem with the UPCI. Or at least tell them to try this first. Had I done this from the start, would have saved time and a lot of reading/posting.
Ah right, that makes sense reading back over it. In that case, I'll make a PR to whitelist the SDL ID of the SF30 Pro in XInput mode if that would work. Thanks for the help and sorry for my apparent inability to read 😅
@bluestang On the Amiberry front, worried I'd have to go off and compile the binary and fiddle around with symlinks and that kind of thing. Turns out, just reinstalling automatically builds the SDL2 version.
Screen tearing I was seeing in Redream seems to be eliminated! Gonna test out Flycast some more too to see if performance has improved.