Hopefully Karabiner will be updated - it's the go-to tool for nonstandard key remapping (in my case, Right Shift to Escape).
If it doesn't get updated, I'll have to start looking at custom mechanical keyboards. Their controllers (some small Arduino variant) allow any random key mapping.
Might be worth noting that Karabiner Elements can be sponsored through GitHub - I would very much encourage anyone who finds it as invaluable as I do, to consider giving what they feel it is worth to them!
The good news is that there appear to be multiple options for taking KE into this new kernel world, and the only cost is dropping support for older versions of macOS. Unfortunate, but not unexpected.
Thankfully PCB was QMK and VIA compatible so nice GUI to flash the firmware with my desired keyboard layout.