Last summer I hung two 4'x8' overhead ceiling racks by using 4x4's across multiple trusses. The only point that actually share a truss are the mounts closes to the wall. As janky as this is, It's probably fine as far as load.
For maximum use I would actually like to take these down and run three 4'x8' racks across the rear of the garage and get rid of the current 'L' shape. I also want to remove the 4x4 hanging from the ceiling and replace with slotted angle bars.
The only problem being that I would have 4 hanging points across two or three trusses as they run parallel with the racks, which could be a no-go given the 10lb a SqFT load of a truss.
Assuming I use the wall studs to mount the back of the racks. Could I distribute the load across three trusses for the front hanging point and be ok? If so how much weight could I hold with each rack? Each rack would be 32 square ft, so given 10 lb a sqft that would be 320 pounds per rack, but since there is multiple racks, I am not sure how the weight distribution would work out.
I've attached pictures of my ceiling, the current setup, what the exposes trusses look like, and a diagram from the top down of how I was thinking about mounting it.
