I've had two mares in my life that I bought as
broodmares, and the seller told me outright that they were cribbers. Both
came with cribbing collars on them. I took the collars off and turned them
out in our pasture, and as I hoped, they did not crib any more.
Environment has a lot to do with cribbing. Neither of these mares (both
TB's) liked being confined, and were quite happy and not cribbing when they were
free to roam. One of the mares had to be confined in the corral for a
while when she injured her knee -- she started cribbing on the
corral. So, I had to put the collar on her again while she was up in the
corral.
It could be that if you have a way to give the
gelding more space in his new home, he will be fine. It's a chance to
take, I suppose. He still may crib on the trailer or fence, or whatever,
at a ride. But the cribbing collars do work. Just depends on if the
horse is really what you want in every "other" way!