I like the idea of xcape for exiting insert-mode by just quickly tapping Control_L, but I don't like how it leaves "unconsumed" escapes around in other modes, or in other programs/terminals, which mess up my flow.
(E.g. input is
xargs █oldcommand and I'm about remove
oldcommand with C-k, so I hit Control_L, then change my mind because I want to type "bash -c" first, but because of the escape that turns into
M-b ash -c leaving me with
ash -c█xargs oldcommand instead of
xargs bash -c█ oldcommand.)
Can Emacs itself handle lone modifier keypresses so I can have this only in evil insert-mode?