My NRL Hunter teammate is making them, a lot of iterations were just to test the plastic holding the steel nut at certain ft/lb ratings. I don’t think relying on the plastic to hold enough tension for threading would be the way to go without much higher cost material. Weight difference is in grams. I know in the one piece captive nut model he’s embedding the hardware and building up the print area to hold it. He does have a website where they will be available and the goal is to just cover print time and material plus hardware. Current model is .65” rise. They’ll wind up very significantly cheaper than the MDT comp model and weight will be not much different at all than LOP spacers. I’m using an OBI Cush Pad on mine to achieve wanted LOP but these with a stock HNT-26 pad should be lighter than that.