I've used over a dozen split- and ergonomic- keyboard over the years, so I am familiar with the time investment. And I do agree, for the most part, that the time is well invested up until a point. But I don't see how requiring additional simultaneous keypresses is "more ergonomic" than pressing a dedicated Ctrl or Alt key. Airplanes, which pilots invest much time learning to fly, have dedicated buttons for all functionality. How is "ergonomic" defined in this context?
I'm not arguing, really I'm asking to hear the answer and become wiser.
I based my keymap off of that of the Kinesis Advantage, which does have function keys.
I have Ctrl + Alt + Super on the thumb clusters, each as their own key. I did copy the default layout for the Ergo S-1 which uses a modifier key (also on the thumb cluster) to access the function keys, so F1 is Fn+1, F2 is Fn+2.
I thought I would miss having dedicated Fn keys but they are surprisingly not missed much in my workflow. Might depend on your workflow though. The current solution is workable, at any rate.
I'm not arguing, really I'm asking to hear the answer and become wiser.