I was sick of the default Windows software (you can't use modifier keys together with the Powermate) and wrote an AHKHID script for it. I'm using the USB version, so I'm not sure if this will work with the bluetooth version.
Per default, I have only assigned "turn left" and "right" to mouseweel up and down.
(You have to configure button press, button press + turn left and button press + turn right on your own)
That way, I can use the Powermate in Reaper for different tasks, like Plugin GUIs
and mixer fader. But additionally, I use it for navigating in my project in conjunction with
modifier keys:
Grab the attachment at the bottom of this post. You need AHK installed on your system in order to run the script.
More info about the script in the AHK forum:
https://autohotkey.com/boards/viewtopic.php?f=6&t=50920