I agree that allowing the two dominant teams to use the Double U Turn both times is bad. Probably best to limit them to one time each, though then the second Double U Turn would probably be needed before the final 5.
I'm not sure why Steph & Kris U Turned Joel & Ashley, unless it was because they decided that U Turning Jillian & Emmett wouldn't knock them out. Perhaps they also thought it best to try and knock out one of the more capable teams behind them and they felt some resentment for the deals they had to make with Joel & Ashley earlier in the race. Jillian & Emmett's U Turn, as they explained it, made sense to me. If you really think Frankie & Amy are the weakest remaining team, then it makes sense to try and pave their way into the finals if you can. In the end, it was clear that having to do the speedbump knocked Rita & Yvette out of the race.
That was a good episode and I enjoyed watching it live. If I can, I'll do it again next week.