Sorry, I don't own this brand 5th wheel. I do, however, totally agree with you on switching the E rated tires out for your G rated ones. I, like you, believe a bit more margin on anything I 'm pulling down the road at 60-65 mph is a good thing.
Days camping (2015)----88 days
Days camping (2016) ---110 days
2016 Wildcat MAXX 28RKX (33' TT), 2007 13' Scamp
2015 Ram Laramie Hemi
30 years RV'ing
12 different RV's