If that's your sweet spot for speed, you may want to look at a tire motor system or upgraded tires on the trailer if you have not already done so. These tires are not rated for extended higher speeds, and I will not claime I have not hit speeds of 70mph but not for extended periods. The stock tires are known to heat and blow out causing some major damage.
If you do have a blow out, remember get on the throttle and not the break, leave enough power in your ram to give that jolt to pull the trailer back straight the bring her to a slow stop.
Glad you like the combination, love my ram 5er combo as well!
2015 Sandpiper 30IOK
2014 Ram 6.7 CC DRW
2006 Charger RT