I'd recommend a split keyboard to anybody who has their fingers on keys for more than a couple hours a day. My shoulders and upper back feel so much better, and I swear I even look better because my posture has improved. Much less tendon pain as well.
Furthermore, I'd recommend the EZ or the Moonlander to anybody who can spend the money. I'm sure you get a large part of the benefit from a cheaper split board, but the thumb clusters and custom keybinds are really really nice.
https://ultimatehackingkeyboard.com/
I'd be interested to see a comparison between the UHK, Moonlander, and Dygma Rise. They all seem to be converging on the same design principles.
I agree, though; having a good split keyboard has been a requirement for me since I first got the original MSFT natural keyboard.
However, I feel it's like configuring VIM - mixed feelings with the defaults but once you set everything "your way", then there's no way back.
I couldn't believe how ergonomic tmux key bindings can be with moonlander's magic.
And Alt + F4 is bound to a double tap of the right red thumb key :D
They (PyCharm, PHPStorm, etc) use a load of multi-key shortcuts which include use of the function keys and it became a real pig to use and ultimately I gave up (expensive - I'd bought 2; one for home, one for work...).
How do others manage this? Have another layer with all the usual keys but replace numbers with function keys? I don't fancy remapping all the shortcuts.
I just don't use F keys, but for number I have a left thumb key that transform the right side into a num pad. You could do the same with functions keys. Or do what I did for any number and permanently remap the normal number positions to f keys as you said.
But the nice part is you get to adapt the keyboard to your own needs. If you only use one or two function keys, you could give them decicated buttons on the may layer. You can even have one button do the whole combo. For example I have one that does shift+insert so I can more easily copy into terminals.
When I bought it, I was just looking for a sleeker and more ergonomic keyboard with a split design, but the ability to easily reconfigure every key on the layout brought a new meaning to the word "ergonomic" for me.
It means that when a particular motion or shortcut that I frequently use is puts too much strain on my hands, I can simply change the layout to make the keys more natural too use. And it's just an overall incredibly well made product.
[1] https://www.zsa.io/moonlander/