> I think I might live with a smaller space bar

On typical keyboards, the spacebar is just about the width of 6 keys. -- Comparing what's allocated to the thumb vs to the pinky: the thumb is strong, the pinkies are weak, but the thumb is only used for the spacebar, and the pinkies for a bunch of other keys.

I've enjoyed using these niche ortholinear or split ergonomic keyboards. It's good to be able to use the thumb for more keys.