Since filming this video I have changed my mount, the new one has a quick release similar to a tripod quick release and it also has a clear hole to allow a cable to enter into the bottom of the CrystalSky, so I now use a 20mm long cable from there to the USB A socket on the bottom middle of the controller.
I’ll maybe add a photo or two of it on here next time I’m out.
I got it on eBay, here is the link
And this is the cable