I am tempted to add lots of XF86 keyboard symbols to that one layer of my keyboard and bind them all to good stuff in my window manager.
https://wiki.linuxquestions.org/wiki/XF86_keyboard_symbols

Right now I have Fn C bound to XF86Calculator to open a terminal emulator running orpie.
https://github.com/pelzlpj/orpie

I guess I did that because I didn't want to be using Emacs' calc all the time. 😁