3.73 vs 4.10 is just not that big of a difference. The 66rfe (6spd tranny) is a POS regardless of the gears. The 1-2 gap is a mile and overall behavior downshifting around 2-3-4 is just stupid.... again, regardless of the gearing.
I've been hanging out on this board and others pretty much daily for 5+ years and can't ever recall anyone testing 3.73 and 4.10 back to back with the same trailer and reporting any drastic difference. fwiw, I can't recall anyone even doing more than a test drive with the different gears. Most of the conclusions I come to just have to be pieced together from different people with similar trailers.
4.56 would seem to be the perfect gear for stock tire size but the tranny spacing and shifting would still be poor.... maybe not as poor but still not great. The best fix is just getting a 2019 with the 8spd
I'm pretty sure that would correct everything.