just found that out, hopefully helpful for others, too: have your powertools equipped and press k. This will bring up a tinker gui showing all available tools on the left. Like night vision, flight control(hover) and the tools.
Now click 'new' and press the key you want. Then just drag&drop the wanted module to it to bind it.
For more than one key binding you can drag the keys around in the gui so you see them all.

I find the only useful things to bind are jetpack + boots (which we currently can't use), jump boost and uphill running.