hahah no chance, I could barely get my hands on this one (live in the a third world country, not much money, etc). I actually tried so hard to get my original PS1 DualShock working but the two adapters I got just betrayed me to no end so I had to upgrade. I know you use another controller and it'd be kind of ridiculous to make you buy one just to test this out but yeah if anyone is reading this and has it working please let me know lol
Also I think the compatibility has somehow improved a lot since I started using RetroFE so thanks for that! Not sure if you've changed much, but again this is the only button that doesn't work, I have all others mapped :p
joy0Button7 is "Options" on my end. And also I'm pretty sure it's joy0Axis2- just out of how the "+"/"-" characters work with other buttons, plus it being a pressure sensitive button (so it's considered an axis one I believe)