Thanks for the follow-up, great information to know and sounds like Jayco is saying don't exceed a 600lb rated WDH, which is the rating of the Reese SC "66151".
A number of manufactures have WDH restrictions on their lite-weight trailer A-frames, always good to check for any restrictions.
2016 GM 2500HD 6.0L/4.10
2005 Jayco Eagle 278FBS
Reese HP Dual Cam
Putnam Class V