For the Piantor you can use beekeeb’s ready-to-go firmware from https://docs.beekeeb.com/piantor-keyboard
It’s QMK with support for Vial, so you can use the AppImage to define key mappings, layers and many other stuff without having to code and compile QMK. https://get.vial.today
So far that was enough flexibility for me, dodging a compile.
Great transparent neon retro style!