A bunch of us are using PlaneAround wingtip and tiedown mounts. It's real solid machined aluminum stuff. Less likely to lose your Gopro with that.
The other day I had a Gopro 360 MAX (much larger than the Hero) on my Zlin50's wingtip, with just a standard stick-on mount. It did fine, but it's a slower airplane than the RV, I was doing around 120kts or so, indicated.
Palm City, FL
2014 RV-10, N311LZ - 700 hrs
OnSpeed development team