so, with these... if you're by yourself, you end up dangling from the side of the house?
This is what roofers use. My brother is a contractor. I helped him do a few roofs. I dont like heights. His roofers made fun of me wearing one until one of them backed off the second story. Luckily, he only broke a leg.
I will feel safer having a harness on.
My Dad and Father in law have rolled off many a roof and they were lucky. I am, however, not that lucky.
I have absolutely no experience with climbing roofs so I won't even go there. Further, I like some of the lit roof lines I've seen here and other blinky sites but I've never seen one that is so cool it makes me want to light mine. Not to mention tearing shingles fooling around up there. Plenty of other places to put lights that offer much less a risk. Be safe.