Really glad this is being looked at. Please consider allowing (under X11, using xkb) Caps Lock to function as Ctrl. This greatly reduces RSI for me, and is important to my painless enjoyment of the game

I would like to confirm this as well. I use the "ctrl:nocaps" above to map Caps Lock to control, but it seems that this is ignored by Factorio (in the sense that Caps Lock seemingly has no effect whatsoever -- it doesn't register as control nor caps lock).