> Long story short, this is the single reason why I haven't bought an ErgoDox/keyboardio/… so far.

I don't really understand this conclusion. The point of these programmable keyboards is you can make them as work-free as you need. If you hit your function keys all the time, you can make the number row produce a function key just by holding it for a little longer or do like what OP did and make number chords match a function key. Press 1+2 to get F1, 2+3 to get F2, etc.

I understand not wanting to use a layer for everything which is why I don't care for ultra minimalist boards like the T-34 or Plank but an Ergodox has plenty of keys for my uses.