I can't overstate how janky this solution is, but in operation it works great. What I'm using: https://github.com/jfedor2/hid-remapper
It's literally a:
Raspberry Pi Pico
a motherboard USB host cable with the motherboard connector cut off
4 solder points to the Pi Pco
some self-fusing tape to hold it all together.
The wiring is as follows, save for the blue in this picture probably being white on your cable: https://github.com/jfedor2/hid-remapper ... apper3.jpg
The configuration software has a "monitor" feature, which you can use to press buttons you wanna remap. Made it easy to figure out that 9001d was my left button, etc.
You can see how I mapped everything below:
It worked just fine in Puchi Carat on the Playstation core. With a 2nd Egret II Mini paddle and the Mr Spinner hack, you want to set the throttle to like, 150/145 or so for them to have similar movement.
At some point I'm gonna make a 2nd adapter for emulation, as Mame lets you map the mouse Y axis to player 2 and I can just map a 2nd adapter that way.
BTW, if anyone actually makes this janky thing as like, a cleaner plastic enclosure, please let me know. I'd rather buy this thing and make it.