List of keyboard "complications" that should become commonplace, from a mostly laptop & terminal user (in descending order of importance):
a. Thumb keys. Long spacebars are a waste of space. Split 'em!
b. A Control thumb key. I might just consider using emacs. Damn emacs' pinky. Scrolling in vim is a pain without this.
c. Scrollers. Those flat scroll wheels or barrels on some keyboards that adjust the volume. Should be remappable; imagine whizzing through tmux windows, cmus track entries... a tonne of unforeseen possibilities.
d. Context Menu key (analoguous to "right click"). Usually found on your typical boomer 2000's GUI desktop setup. I sometimes miss this on my laptop.
e. "fn numpad". Some keyboards have a mode where m=0, j=1, k=2, l=3, u=4, etc. I've not much experience with it, but could be useful with rapid entry. But software can also do this, so meh.
ThinkPad mouse "bean"? I haven't fiddled with it, and doesn't look effective.
Flat joystick? I have a keeb with one and it sucks.
Split/Ergo keebs? I tried the Moonlander, wasn't for me. I like my keebs flat and low.
That's it. If a keyboard with the aforementioned complications exists, please bombard me with your wisdom.