Not sure if your horse would eat them, but my “hotter/nervous” boy loved his soaked timothy/alfalfa cubes, and I never noticed an attitude change in feeding them and he’s the type that would let me know!. I would give him a generous scoop soaked about an hour or two before I rode and it worked wonders for him! I did this about 3 x a day when he’s at a show. He loves them and I continue to feed them 1 x a day through the winter and even now when hes on pasture. It kept the weight on him and I always felt better that he had something in his stomach before I showed.
I still feed timothy hay as well and he would pick at that in-between his cube feedings.