Same issue, regarding shifting, no missing though. Once the transmission has downshifted after slowing down and throttle is applied again there is definitely some slack. It feels like slack in the driveshaft u joints or something similar. Slight clunking and not smooth. I mentioned to the dealer...
I was just thinking about doing something like this yesterday. I didn't think I would really have much use for a full trail rail system, but if I do i can just make my own and still utilize these anchors in the future. Thanks for the tip, just ordered what you recommended!