Good info.
There is gonna be a bit of a learning curve with clutching for your sled so be prepared to wrench a bit on the hill. There's just no way around it because you will have to make adjustments one at a time and each change will hopefully get you closer to where you want to be.
In a nutshell, here's what I think is happening. Your weight may be too heavy in the primary and in addition, the secondary is opening up too fast which will cause terrible back shifting and tremendous belt and clutch heat.
I recommend to stick with just the weight change on your next trip out. See what the Rpm's are. After a long climb open the side panel and touch the faces of both clutches. Whatever clutch is the hottest, that is the one you will want to work on next.
Clean your clutches before you go and practice taking apart your secondary. You will need to do some spring changes on the hill.
After your rpms are in the 8100-8250 range, start working on your secondary by changing to a stiffer spring. Buy 2 different stiffer springs before you go. The stiffer spring will allow your sled to stay in low gear longer as this is what you want for boondocking.
It's near impossible to tune clutches perfect for all conditions so you will have to settle for a somewhat all around setup.
Good luck!