Ok I think I got this. Scrap the associations idea, set them back to blank, it wont work the way Zooz has the ZEN72 firmware setup. It would probably work going to a ZEN2x unit though with param #17 set to 1. I will have to send them in some bug reports based on this thread to get it working correctly eventually. @agnes.zooz
I added the startLevelChange and stopLevelChange to my dimmer driver. My ZEN77 I tested on did not honor the the dimmingDuration setting so I did a little hack where it temporarily changes the rampRate #9 to match the dimming speed #16 and then sets it back again. I had to put in a 600ms delay for this to work. The LED on your switch will flash a few times when you use this command from the param change. Seems like the dimming down is much smother than the dimming up but it might just be the cheap bulbs I am using, it does the same thing when I hold the dimmer paddle.
So... you should be able to set the startLevelChange(up/down) on the button hold, and stopLevelChange on button released, and it will work!
I posted it to a development branch on my GitHub (not in HPM yet). Click the "Raw" button to get pure code for copy/paste or import.