The way I would set up my rig there would be no need for extra gear. I would make my tree hugger with one 1/2 twisted loop in on the end. I would wrap it around the tree and feed the tag end through the cup-side of the loop and tighten on the tree. I would have the rap ring on my whoopie sling with a pin tethered to it. Build the Line Locker insert the pin. Repeat on the other end and adjust my slings.
You loose the need for knots or any hitches in the webbing (which reduces the brake strength). Granted a hammock fully rigged and occupant will not exceed a fraction of the B/S. You can just tie a straight cord rigged hammock to the rap ring. You can also use this for webbing rigged hammock, just lay one on top of the other and build the line locker as normal.