I was wondering if the steer had been held back for maturing reasons, to try to hit a certain show date, or if his weight was just a result of his actual ability.
Without knowing the calf, I guess I'd suggest giving him a more consistent routine. Finishing fats, be it in the real world or the show ring, is all about the details. Doing the exact same thing at the exact same time every day and making adjustments in small steps is always best. A steer does't need turned out into 7-10 acres. Assuming this is a grass paddock, he really doesn't need that either. Allowing him to have that forage source every other day is giving him the choice of what and when he eats and causing his rumen populations to fluctuate. The microbe populations used to process forage are not the same as the populations used to properly digest a high starch ration. You've got to build the population you want to use over time, which leads back to consistency being the key to pushing gains. Even the flakes of hay should only be given in an amount that's just enough to provide adequate scratch factor, rumen flow, and gut health.
Rinsing him 4 times a day could even be affecting his performance. Cattle naturally have a graze/rest cycle they establish throughout the day. It even fluctuates depending on the time of the year. You're replaced the graze with the bucket, but if you're getting him up to rinse too often, or at the wrong time, the rumen and the body in general aren't being allowed to settle into a proper somewhat natural routine.
Feeding cattle is a bit of an art form derived from a bunch of science. It's why so many "my steer won't eat" questions basically go unanswered online even though some very experienced feeders probably read the question. No mater how many hours of ruminant nutrition you've sit through or how many years you've read bunks in the real world, if you can't see the animal/routine in person you're often basically left making a wild ass guess.