Hi Mark.
Have you managed to move this functionality to a Moodle 3.2 or 3.3 install?
I copied your approach successfully last year, for which our staff thank you very much, but my attempt to get this working in 3.3 is not happening. I've only tried to copy and override the mod_chooser funtion with no code changes at all so far. I generate zero PHP or Javascript errors but the "Add activity or resource" link is just a dead string with no ajax/yui click functionality.
Do you know of anywhere which documents a working approach to this?
Cheers
Oliver