OP - I looked at the photos of your cylinder and compared them to my 627PC and mine looks identical to yours. I have not had a hang up problem with moon clips (mine are Revolver Supply 25mm - the 20 and 22mm do not work for me other than with Winchester brass) as long as I am using Starline brass with some sort of truncated cone bullet. As soon as I use anything like a SWC or anything with a lip or ridge, I will get hang ups.

I will note that I still need to "jiggle" a bit more as compared to a 625PC moon clip re-load. Those seem to be like guided missiles and I think it has to do with the spacing of the chambers in the cylinder. I'm not so sure that you wouldn't have a similar situation with the TRR8 given that you would still be working with an 8 chamber cylinder.