I wish I am talented to mod the Ergodox and move the thumb section closer, but I am not.
My current solution is to use a layout so that I don't use most keys on thumb section (with thumb).
Basic idea is to move enter to where space is, and use the keys under the letters as space. Like this:
Seems reasonable enough. How do you like it? (Personally I find the primary thumb key a bit easier to reach than the bottom-row index finger key, but the little gap right between them is also quite convenient.)
I am used to hit alt with thumb in normal keyboards, so adapting to bottom row is pretty straight forward.
I also thing that the little gap should really be where the first thumb key located. Though that could require a non rectangular key for that place, perhaps the makers of Ergodox thought that is a problem.
What I really want is that the bottom index key and the gap merges into a 2x key for space. I see lots of people are already working on those ideas.