The "set" screw is a set-it-and-forget-it option. It has a quick release latch once you size it to your handlebar.
I could see a simple DIY version that would be even stronger with the appropriate go-pro mount. Probably something TerraCycle could machine up and offer. If I had a GoPro, I'd design it at a mere percentage of sales, of course. It really is a no-brainer if you have the tools.