If I wasn't already using caps lock for backspace colemak style I might have gone for it as an escape key. Shai Coleman (the guy who made colemak) uses the tab key rather than escape to exit modes. While I don't know if I'd want that either, it does remind me of how I really think that we need to get /something/ to replace the tab key one day in one of our group buys.
For now I'd be happy with Vim on escape since it's pretty symbolic, might be a bit hard to get the quantities needed for other locations I fear but you could always try of course. Also, if it was doubleshot on a green background, it would be too close to my green shifts from RGBY kits.
