I, didn't like the idea of wedges either. Last time I had to deal with the issue , I drilled one side, and the bottom, of the tube and tapped a 3/8" bolt into each, with enough exposed threads for a jam nut. Put the receiver in, tighten the bolts, tighten the jam nuts. Towed for 20k miles using this set up and no problems.
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.