Split keyboards can help with wrist positioning but not finger travel, both of which can contribute to wrist problems.
For reducing strain to access keys like shift/backspace/escape/tab, I think that's where "use keyboard with multiple thumbkeys" would have a benefit, yeah.
I've got a 42 key split board so I'm not a total noob to minimalist keyboard but struggle to see how 34 keys can be used effectively.
In reality it would be easy to go down to a single thumb key, making it 32 keys.
In short I have layers for numbers and symbols, I make heavy use of combos (pressing multiple keys at once) where I have modifiers, big keys like escape and enter and also the numbers and symbols (for typing singletons). I also have different functions for long press and I use capsword and numword (caps lock / layer that turns off intelligently).