I have the axle straps, they are nice but I actually stopped using at the recommendation of someone who has hauled a lot of Broncos to customers on long trips.
The problem I have experienced with those short axle straps is that when you have multiple straps mounted at one point on the trailer and the truck being hauled, is that they tend to work loose as the load shifts, which leads to whatever is being hauled sliding around on the trailer or flat bed.
To prevent this, I have been using two long straps, one for the front of the trailer and the front axle, and one for the rear of the trailer and the rear axle. I start at one corner of the trailer by attaching one end of the strap then feeding the strap under the axle, across the back of the pumpkin, and then Around the other side of the axle and then attached to the opposite corner. Once you do this and tighten down the straps really good, they do not come loose due to the dual mounting points and the two straps being in tension with each other.
It’s difficult to explain but hopefully the pictures will help. Of course, with only two straps they better be thick and high quality, and you need to have super solid mounting points for the end of the straps. Also you need to take care to route the straps carefully so you don’t mess up your brake lines or anything else. Due to the clearance under our Broncos, it is a lot easier than with a car with a lower stance.