Same. Called carry handle, I never saw anyone put their hand there after our initial break in period. I ran into a squid that had his sling hooked through the hole in the bottom of the sight. I got far away from him.
Before I got issued my first M16A4, I was looking at Z type mounts that attach to an A2 style carry handle but add a top and forward sitting rail. I knew (even as a young private) that the Army was going to optics eventually and considered getting one of these for my A2 rifle.
https://www.opticsplanet.com/ncstar...andle-mount-with-side-weaver-mounts-marl.html