I think that split space (space on left, backspace on right), should be standard on larger boards.
Right thumb for backspace? Interesting.
but why is backspace so far away nowadays? It’s 2u vertically and like 1.5–2u away horizontally with your fingers on the homerow on a standard board, and you’re using your weakest finger for it. Most typists aren’t 100% percent accurate so backspace is going to be used quite frequently. Makes the most sense to have it right next to your space key and using the strongest digit on your hand.
I don't have any problem with the backspace being on the upper right corner. The top corners are prime keyboard real estate; I use them to locate my hands on the keyboard, and they're impossible to miss for Esc and Backspace. I use my ring or middle finger, depending on where my hand happens to be at the time.
Also no reason for caps lock to be on a 1.75u key. It’s not useful enough to warrant that large of a key.
I use a remapped 84-key PC/AT board, with the former CapsLock on the bottom right mapped as Right-Control; I use it frequently by moving my arm to the right, using my thumb on it, and my little finger for the + or - keys so I can adjust the font size on web pages to something readable.
I never used CapsLock, ScrollLock, or Numlock for anything, and remapped those long ago.
[rant] The lower left corner is the ghetto of the alpha block. It's very awkward for me to hit, and with my hand size, control-alpha combos are outright miserable on a 101-key board. And that's right where some sadists chose to put the Control key...
As an aside, the standard key spacing was developed for average female hands. I have jumbo-size male hands. That affects optimum key positioning a lot.