I kind of regret my glove80 purchase after getting on the ortholinear ergo bandwagon to replace a microsoft sculpt. It's solidly built, happy to support and I'm using it to type this currently as a sunk cost fallacy... but similar concerns re: the inner thumb clusters being difficult to reach without repositioning palms. I've mapped them as: alt and space on the inner left and alt+space (power toys search) and layer on the inner right with another space on the right closer to my thumb. That's the biggest game changer vs. another keyboard: having backspace accessible with the left thumb and space with the right thumb is amazing. I also cannot reach the bottom outer 2/3 buttons with my pinkies and have 'medium' glove hands. Also for the cost, I was disappointed that one can't individually control/map the RGB LEDs so what is the bloody point of having them.
Glove80 is a decent ready-made product but it's simply too big. From my experience, sofle/silakka/lily58 with tenting solution worked better since they have smaller thumb cluster and surface but still takes advantage of same structure.
The ones I listed are well open sourced and modularized, you can print out parts as you go - trackpad, trackball, tilting pad, joystick whatever you want.
It's such a disgusting modern day leviathan, I roll my eyes to the back of my head when people casually say you should buy their stock