I recovered from a deep dive into mechanical keyboards by trying Topre switches, the obsession killer. I now have four Leopold FC660C keyboards with Hasu FC660C controllers, with custom QMK firmware.
After many experiments, I've been won over by making every key near home row a "tap / hold" key. Tap for usual keystroke, hold as a modifier to access a custom keyboard layer with the other hand.
This is an empirical question. I've learned chording keyboards. I had the original FingerWorks TouchStream multitouch keyboard, tech which Apple turned into the iPhone. I've owned various ergonomic and small keyboards. I've tried many versions of my own firmware. I learned Dvorak on a one-handed half keyboard, and experienced the miracle of knowing how to type Dvorak both hands with no practice. Brain plasticity is very important to me; I've tried everything I can.
"One finger each hand, near home row" is stripped down chording that wins hands down over any other typing system I've ever tried. Taking advantage of the quadratic address space (versus a linear multiple using a fixed set of modifier keys), I control every aspect of my computer this way.
"Control-Xylophone" has kept me from ever accepting Emacs. I should write a two finger chording interface to Emacs, in the spirit of Devil Mode.
Leopold FC660C Mechanical Keyboard https://mechanicalkeyboards.com/shop/index.php?l=product_det...
Hasu FC660C Controller https://1upkeyboards.com/shop/controllers/fc660c-controller/