This may apply more to others than you as you appear to know what's going on. You sure you can't get a two batt tray on it? They also have bike racks for the front if you bike or storage I believe. These things attach to the frame somehow... I've seem em but not up close.
But If you don't have them, adapt the front for two 30 lb propane tanks and add a second battery. That should take care of most of it for most people. If your generator will fit in your front storage put that in. Put any heavy stuff there...like you have. If you presently have one of each with the propane being the smaller one, you could get maybe 120 lbs increase roughly from the changeover to two batts and two 30 lb tanks... I think a batt is around 45 lbs. One 20 lb propane tank FULL will run in the 35 lb range. One 30 lb propane tank will weigh in the range of 55 lbs full...
So, IF a person has one and one right now, they are adding approximately 80 lbs to the tongue weight. If you have two 30 lbs propane tanks (FULL) and two group 24 batts, you are talking in the 200 lb range with around an added 120 lb's to the dry tongue weight over a basic set up. Unless it's Tuesday in the Himalayas...
I'm sure someone will correct me and talk about atmospheric air pressure and the impact of heat on the amount of propane you can put in a tank etc. This is ballpark with basic equipment packages and you can buy the trays for these things online and install them yourself relatively inexpensively. I actually would have preferred two 20 lb tanks and one batt on mine as I am at the mark on my truck capacity at present and would be OK with 120 lbs less... So, I was calculating this kind of thing.