Since UIM didn't want to play ball after installing Ubuntu 12.04 from scratch, I tried IBus, since that's the IME framework that's coming with Ubuntu by default.
However, ibus-table-compose is a pain in the butt to use because just to enter one character I need to press the key combination to trigger IBus first, enter the respective compose sequence, then press the IBus key combination again to disable it. Instead of that I'd rather like to keep my compose key functionality as provided by XIM, since that requires fewer keystrokes.
The problem is, though, that when the default input method is set to IBus and IBus is deactivated so that (AIUI, since I started it with ibus-daemon --xim) it is bypassed in favor of XIM, the settings in ~/.XCompose seem to be overridden by IBus's own version, so e.g. Compose c a doesn't give ą (a-ogonek) as I defined in the .XCompose file in my home directory, but ǎ (a-hacek), as defined by some other settings.
I've grown quite accustomed to my own mnemnonics, so is there any way to make my system use my own ~/.XCompose file with the default input method still being set to IBus so that IBus will still work e.g. in OpenOffice and other applications that don't let you choose the input method with a context menu?
Note: This is not a duplicate of the question How can I get compose back on ibus?