Generally speaking, returning true means “I did something”, and it prevents the event from generating more matches. In this particular case, I’m not entirely certain why I did that. There may not be a reason that matters (anymore).
I think it’s just a comment to remind myself that there is an unused button sequence that could be used for something. This was before triple- and quad-clicks were added…
This is mostly something I do for debugging reasons, and mostly when working on new hardware.
Usually when I port ProffieOS to something new, I disable all features, make it compile, then enable one at a time until everything works…