This is not in any way endorsed by Avalanche, it's just how I pack my bergen when going for a wild camp in the hammock. The only thing that is different is that obviously there wouldn't be 10kg of weights disks in there, I would have added my cooking equipment, food and wash kit.
The reason I've chosen my hammock kit instead of the tent is because the hammock kit is all soft, with no corners to risk digging in my back, almost like having a tightly packed bag of cotton wool, especially at the bottom where I have the equivalent of two sleeping bags. This will fill the bergen to maximum without anything being loose inside as the bergen has no compression straps. The 5kg disk at the top will help with correct posture while carrying the bergen as the equipment is almost uniform in volume-weight ratio. Also if the worse did happen I will have all the equipment I need to survive a night on Pen-y-fan in relative comfort. Shelter including a tarp, bivi bag and a -15 degree sleeping bag.
On race day the extra 5kg disk will come out, as the weight requirements are 35lb plus 3litres of water plus food. I will be keeping the waterproofs in there as extra weight as I don't want to include them in the weight and get caught out at the check-point wearing my waterproofs and have my bergen under weight.