Ok, after messing around for a bit with the different solutions and it seems that there's no reliable way to control LED feedback. Jeff's abstraction is super erratic, controlling multiple/neighboring LEDs all the time, not to mention needing a separate abstraction for every possible state of each button (rather than being dynamic/message based).
The official/external-based solution seems to lose connectivity when chatting to the LEDs sometimes (only fixable by unplugging/replugging back in). This also seems to turn on in default mode (EL on and SOFT/STEP flashing, which isn't classy).
The Stefan version is oodles of abstractions (with dependencies on a whole other library), which makes it unruly....
I'd be happy with Jeff's patch if the LED stuff worked right/reliably.
I also tried coding up a matrixctrl type 'only one dot per column' so that you could go from color to color and state to state, without having to manage where you've been, but timing is an issue as I'd have to turn everything off between each color change.