The added weight is negligible, open sections aren't bad either on the hands, I still have my DD Omega quad that's still on my Colt that I bought it for. Still works and on that short of a length of rail on a carbine gas length with FSB, the extra width is negligible, really as the thumb break method to me is really better to use to grip with in conjunction with a VFG to use as a hand placement and hand stop.
I use a Magpul rail on top, and https://bravocompanyusa.com/xt-rail-cover-black/ for the sides and bottom. They're user friendly to resize and custom fit for whatever reasons.