Page, as always FWIW, and market dependent, having a smaller trailer that a machine can move (currently I carry my mini on a 5x8 with the grapple, or in my chip bed), can help a lot on big properties, as you can move all the gear you need in one shot with the machine, instead of many, many trips by hand.
Also, its good for dirty rakings and stuff that need to go to the dump. I removed three large trees in a backyard. Filled many cubic yards of dirty rakings into the trailer, rather than having to take it out to the road in cans/ tarps.
Also, you can load wood into it directly, where you might not be able to take a big, heavy dump trailer. If you have friends wanting wood, you don't have to manually unload it, just take it to their place and park it. Especially, if you can get them to bring the trailer to the jobsite, and from the jobsite, saving you driving.
Also, I can put a full sheet of plywood on my loader arms and grapple to carry plywood for a plywood roadway, or put lots of gear on the top of the plywood to save lots of trips with gear, if the access if flat enough.
We have a lot of 5 acre parcels here, so that can save a lot of trips.
BMGs come with the L-bracket now, I believe, for inserting a tow slug. I don't care for the round tube that goes into the grapple. I don't know why its not square. I stabilize it with the grapples' tines.