After I got my GoPro, and the line mounts besides my home made, I ordered a handful of different 90 degree "arms" from different web manufacturers (cost almost nothing), so I could fiddle around with them and see which worked.
And found they had loads of good uses, one as seen here.
When using a safety line almost hidden (yellow line), you wont risk losing anything so no risk
Only thing is, you should not "pull" the lines when you start alone, as you might accidentally change the camera angle, but you will learn to avoid this.
One learn not to do this anyways, as you could risk getting sand on the lens, so goes without saying really.
But you have to learn first the hard way ha haa
Peter