But when not looking at the keyboard, having full height left and right arrow keys makes them feel just like the nearby Option and ? keys. Having a distinct arrow-key-group shape makes them easier to locate by touch.
It's not always easy. If I need to quickly move to the arrow keys (I touch type, so no looking!), I have about 80-85% success finding the right key on the first press... with the inverted-T layout, that's about 99%.
There's something weird about the way my brain handles the key being the same size as the option key next to it, and the fact that the tops of all those keys are exactly the same.
If you touch type then learn the OS X shortcuts of CTRL-B, CTRL-F, CTRL-P, CTRL-N, far more efficient than moving your hand over to the arrow keys and works in (virtually) all places you are editing text.
I don't think I have anything special configured for my Mojave setup and these seem to work for me. In particular, I use Ctrl + Shift + F2 (on my external keyboard) to focus the menubar and then I can use Ctrl-b and Ctrl-f to navigate back (left) and forward (right) between menus, Enter to select a menu, and then Ctrl-n or Ctrl-p to navigate next/previous entries in the menu, with Enter again to select.
Interesting! I always use Cmd-Shift-/, which focuses the search field in the help menu, and Ctrl-b and Ctrl-f do not escape from there.
But focusing the menu bar with Ctrl-F2 does indeed allow me to use Ctrl-f and Ctrl-b. And after hitting Return to open a menu, I can use Ctrl-n and Ctrl-p to navigate down and up.
Interesting.
I will have to try more, but I still think that there are places in macOS where Ctrl-b and Ctrl-f do not work, and I have to use the arrow keys, instead.
When you're searching for the arrow keys, the break is one thin line only in the middle of one key. When the keys are half height, there is are two large gaps to find. The difference is a few mm vs almost a cm and 3 targets to find vs one.
