So basically, you are looking for a way to toggle Bass Inv with your feet?

Easy enough with the G70… it was an FC7 choice. Don’t have the E50 manual handy right now. Does it have a Control Pedal input choice that can be set to Bass Inv? The Control Pedal inputs could be either a switch or a continuous controller. If you are willing to forgo an expression pedal, maybe that input could be used?

The deeper problem seems to be your reluctance to embrace the whole ‘One Performance (or two, or three!) per song’ workflow. A lot of old school players seem really locked into the old system of selecting styles and sounds on the fly, and unfortunately, the darn things got so complex that isn’t really a good idea any more.

My solution would be, turn off all the Hold stuff (as you’ve noted, it doesn’t always work right) and simply write two identical UPG’s per song, one with Bass Inv on, one with it off. Without a G70 you can’t really toggle between the two with your feet (you only get either Perf Up or Perf Down as a control pedal option, not Perf Up/Down toggle) and use the screen to select them on the fly.

I agree that it’s a bug, but it’s a fifteen year old bug, it’s not going to ever be addressed.

There comes a time when we just have to step away from old habits and migrate to whatever works with newer technology. If you prepare a UPG or two for every song you do, you should be good to go…