i think i'm going to try the design as I have it first though, since i have a lot of scrap tubing and i can cannibalize my long board to test it out first.
looking at some of the rhino t-load videos, i'm not too comfortable with the amount of swinging that happens with the stand when it goes from the ~45 back to upright.
one key concern i have with the current design is that the roller is offset from the center from the hitch, and with a lever arm of ~3'6", i don't think the angle support will be sufficient, especially when i'm trying to put the kayak on. I may look at having a telescoping pole that goes down to the ground instead.
project for next weekend.