The previous owner of my BX drilled a hole to mount a trailer ball. I have used it for some small trailers I have and it worked okay. Biggest issue is that I can't see the ball while sitting in the drivers seat.
I only use it if I have an implement on the 3-point that I don't want to take off at the time. If I don't I use my receiver that hooks to my 3-point. I can see it from the drivers seat so it is way easier to hook up.
The previous owner welded a ball to the top rail of my FEL bucket and while i CAN see it, it limits how low of a trailer tongue I can get under. I have to set the trailer back down with the tongue jack extended all the way, or on some tall blocks, otherwise I cant get back out from under it. If a trailer has just come off a truck at a 'normal' parking height, i cant get under it to begin with. In that case i simply lift the tongue with the bucket edge, extend the jack or add blocks under it, and then hook it 'properly', but it's still highly imperfect and not where I would have welded it if i had my way. I will cut it off someday.
I like using the 3pt to line up trailer balls quite a bit more, and here's a big reason which i never see anyone mentioning: If you leave your stabilizer links loose and are on a small tractor (like a BX) you can actually reach back and shift the thing side to side several inches by hand. So you don't even have to be perfectly lined up, as long as you can reach back and push on the top link a little while your other hand lifts the 3pt lever up until you're coupled.
I am going to be trailering in some gravel and river rock. I am hoping i can use the ball on my FEL to raise the front of the trailer to dump the rock so I don't have to shovel it. We will see if it works......might be a great idea or it might crash and burn......
I have actually done that. The issue I had was i was using a 5x8 utility trailer with expanded metal decking, so it took a LOT more angle than i thought to get the material moving, and since my small loader doesn't have the lift height to stand the thing up on end, i still had to get out and shovel probably the last 20% off the trailer. I think if you are using a trailer with pretty much ANY other kind of decking, it will work just fine. Even if you can't get all the rock OUT of the trailer, you can still get everything from the front to the back so you can reach it with the loader. If you're just trying to slide the rock out of the trailer and not actually carry it somewhere, pulling the rock out with a landscape rake (handheld variety) is less effort than moving it with a shovel.