I don't use any kind of boot. My horses don't interfere and we don't jump or barrel race, so there's no real need.
When I used to take lessons, my Dressage trainer insisted on tightly wrapped polos. When I jumped, I used splint boots or polos, but only for jumping lessons, not daily. I used them to protect the legs from occassional fence rubs. I had original SMBs too, but found the polos easier to put on, lol.
Injuries happen when you push a hore beyond their fitness level. As long as you take your horse a long slowly, building up muscle and tendon strength, you don't really "need" support boots, unless of course your horse knocks into himself. And if that's the case, I would get a second opinion from another farrier, to see if the hoof trim is the cause of the problem.