I am having the issue you are trying to solve. I am using Pacto boards which are x-input. Everything works great except I can get LEDBLinky to see the left and right trigger inputs. The buttons function and RGBs work. I just cant get the RGBS to light in MAME.
When I use the "quick code function in LED blinky, they automatically pick up every input except for the 4 buttons which correspond to the triggers (2 each for P1/P2).
I have tried using your Googlesheet and instructions. My question for you: where do you find the input code "JOYCODE_1_SLIDER2_NEG_SWITCH" within LEDBlinky? That isnt available. I am not quite understanidn what this input code is doing. Perhaps the additional context will help me problem solve.
Any help is appreciated. Thanks!