[l_t]

Sure! I don't have the GergoPlex keymap on Github yet (still a WIP, that one...) but I used the modal chords concept in my Faunchpad keymap as well. Here's the .def file with "modal chords" in it (the first parameter is the layer aka mode, then the rest are the usual ones.)

https://github.com/luketurner/qmk_firmware/blob/master/keybo...

The forked engine (with very minimal changes) that's used in that keymap is here:

https://github.com/luketurner/qmk_firmware/tree/master/keybo...

The only change is that all the chording macros (PRES, KEYS, etc.) accept a QMK layer number as the first parameter, and will only activate when that layer is active. The end result is similar to the "sticky bits" functionality, but without the side-effect of masking the signal of those bits.

This is my first foray into embedded programming stuff, so I can't promise I didn't do anything dumb in there. It seems to work for me, though!