I've got a helmet mount as well on my full face, but I have yet to give it a go. Like you I don't use it often enough.
I think you could probably do a solid review of the Planet 3 speed sensor and get some traffic on your channel. From install to impressions, probably make 2-3 ~10min videos on it. One of them will probably catch. I know a lot of people are interested in derestricting. I've got a Bafang DIY Cromag I put together for commuting. It's a beast compared to the Rocky. Doesn't look near as clean but it has way more power and a thumb throttle, along with fenders and other stuff for commuting. It will hit 34mph with a bit of tail wind and a full charge. It's honestly pretty scary.