Let me share what I have learned with my BX. I have a 22ft camper and 16 ft trailer i moved with my BX. At first, I used a 2 inch ball on a drawbar from TSC to put in 3pt and closed the latch on trailer. IT works, but with the camper if the BX front end is up higher then the back wheel due to the grade on hill, the trailer falls out of the 2 inch ball because the drawbar turned and swivels.
I swapped it out with a correct 2 5/16 sized ball. I had to drill into the drawbar using the silver and deming bit from HF to make it fit. It works, no longer falls off. There is a but! in here. When turning, I hated the way the drawbar is at a angle when it swivels esp. when backing up. I ended up welding a bar in a upright position to hook on top link. Now the hitch is perfectly aligned with ground grade in up or down position . It works perfect like it supposed to.
Just keep in mind with your empty enclosed trailer, its a great idea to have the FEL on for front weight, otherwise you can do a small wheelie if stop suddenly, or on a hill.
Some say the BX is too small, I say its fine as long you have right equipment and counterweight. You can use the 2 inch ball for 2 5/16 trailer as long you can stop the bar from turning. They have drawbar stablizer, but TSC ones dont fit on the BX due to turnbuckles in the way. I also personally dislike the drawbar stablizers due to fact that when you raise the 3 pt, the drawbar is facing towards the operator, and when lowered to the ground it faces towards ground.
Last week, I took a old 1 1/4 hitch I saved from long gone caravan and cut the ends off so its 27"wide. I bought a cat1 drawpin, and toplink pin from TSC for under 8 bucks. The nuts on the cat 1 pins fits perfect inside the square tube so I just welded it in place and filled in the gaps with welding. welded a tube for toplink and it works perfect for moving trailers.
To sum it up- whatever you get or build, you need to stop the drawbar from turning and that is with the toplink for safe moving of the trailer.
Sorry about long post- but wanted to sum it up from my experience.