FN Yellow can provide common programming keys in LH
I notice that the RH layout for FN Yellow is very close to the ErgoDox EZ "Coder Layer" (see https://ergodox-ez.com/pages/our-firmware). Can the LH for FN Yellow also have a similar mapping? These keys are used all the time in programming, and it would be nice if access to them could be made easier.
Yes, you can fully program that layer to add keys on the left side, also. The layouts shown are just the defaults, but can be fully customized. There are up to 6 programmable layers that will store in the device at one time. You can save unlimited layers in the software, but 6 at a time stored directly in the device.