This. But on steroids. One of the primary reasons I went with the ErgoDox was to reduce the load on my pinkies and add some load to my underused thumbs. I have left thumb doing space/backspace, and right doing enter/tab.
I've got Space, Bk Space, Shift/(, and Alt on left thumb cluster; Enter, Tab, Shift/), and Esc/Ctrl on the right thumb cluster. Pinkies have far less to do now.
I really should do something better with the thumb cluster, particularly that third easy to reach key.
I have Win/Esc left of 'a' and Win/' right of ';', and Ctl/z and Ctl// in the z// positions. The whole lower row is basically unused. Win because I use i3wm and use Win a lot for window navigation.