I'm not sure you understood what I mean (that's what I get for not writing clearly). The issue is not that ctrl+enter doesn't trigger on INPUT (I know it does), the issue is also not that /! commands don't trigger on INPUT (that's a good thing: you don't want 'evil' scripts to intercept a "/!remote off"), the issue is that /!commands combined with ctrl+enter will not trigger on INPUT...
eg.
on *:INPUT:*:echo -a triggered!
Type /test and press ctrl+enter. "triggered!" will be displayed, and "/test" will be sent to the current window.
Type /!test and press enter. You will get no "triggered!" and the usual "TEST unknown command".
Now type /!test and press ctrl+enter. You will still get no "triggered!", and "/!test" will be sent to the window as text. That's the problem.