I built wooden boxes, affixed 2 rings to the bottom on opposite sides and use double ended snaps to hold hay nets in the bottom of the box. So they can eat in the normal, head down position. They can spin the bag with just 2 snaps, so I probably should put in one or 2 more. It seems to work out best to have 1 more than the number of horses, so I have 4.
I also put wheels and a handle on mine, thinking it’d make it easier to move them in/out of the huge run-in I have. It kinda works. Need bigger wheels or lighter boxes. Still trying to figure out that.
I really like the Nag Bag hay nets. I have 2 sets of 4…half have 2" holes and half have 1.5" holes. Works very well for my pony and 2 minis. 1" was too small with the hay I have. Two of mine have EMS and one is a winter hard keeper. They’re all at healthy weights. Putting out 2-2.5% of hay every day works well, and mine absolutely do self regulate.
Biggest plus…for most of the year, putting hay out is a once a day chore. During winter, that changes.