Overdrive on USB Pedal?

I can't tell if I'm just stupid and can't figure out how to get it to work, or if its actually not possible with the way this game handles inputs, but does anyone know how to use a USB pedal to map the overdrive button to? I use a PS4 RB4 Jaguar, which I love, but it can't use tilt or whammy controls on PC. On Clone Hero I've just bypassed this by using a USB pedal which I mapped star power to, but it seems that YARG handles inputs differently (unless I'm missing something). I can't figure out how to get the game to use inputs from multiple devices at once for a single player. I know the game is still in development, so maybe that functionality hasn't been implemented yet, but I know its a decently common setup so it seems odd if it can't be done in this game. Has anyone managed to set this up or found any workarounds (low/no latency hopefully)?

Please help, I'm having gold star withdraws.