Hi xMacias!
So, that wasn't quite what I was looking for, but it got me on the right track, so I did solve it!
I wanted a click-down+ key-down on a keydown, and a click-up+key-up on a keyup. I wound up getting there by doing half the events in one macro, half in another, and using the "second event" to map the second event to the key-up. Works perfectly!
Thanks for the hint! Not sure how to embed screenshots, but the 2 relevant shots are attached, for anyone interested.
This was to map rotate, pan and zoom in Zbrush to 3 G-keys, FYI. Works great.