After a couple of scares towing heavy loads, I did some research and had fitted a Rear Disk conversion from Pedders. It is Fully Engineered for ADRs and has their back up of spare parts etc.
I could have got Pedders to do it, but I have a great mechanic and we did it together in a few hours.
Not for the home mechanic like me, as the wheel bearings have to be replaced.
I also got the matching ceramic front pads which helped even more.
I've now done the same trip with a similar load and no brake fade.
No more adjusting drums, no more mud and crud in the adjusters.
I believe they also do kits for KUN26