Their position is that having food in the stomach protects against ulcers, and that makes absolutely no sense when examined logically, whether it's forage or not. And yes, actually, you can colic a horse by loading it up with hay before you work it(not just moseying around, working). I've done it, but only once and only when I was 12 years old and I caught a world of punishment for it and I am smart enough to learn from that. Obviously a handful of hay won't bother the horse, but protect against ulcers? Who's suggesting it does and how does it do that? Because..... That food is OUT of that stomach in 15 minutes. That is a fact. Unless one plans to work the horse for 10 minutes total (and you already stated you don't), that food simply does not stay there long enough to do anything about anything. And unless it's a small amount, yes, in fact, horses colic if their stomachs or what comes after their stomachs is overloaded when they work hard. Doesn't matter if it's hay or grain. It's about amount of feed and the intensity of the work and some horses are more sensitive than others, obviously, but those are not myths. In the wild horses grazed all day on very sparse pickings. At any point they could yank their heads up and run for their lives for a brief few moments. They never at any point had much in their stomachs or any part of the system after the stomach. That's what they are designed for. Our hay nets, feed buckets and all that, we feed them a lot, and the work is concentrated into one hour a day and lasts longer than a moment. So we have to accommodate that system. Keep the load light before that work, and let that system rest after work. As for rationalizing backing a horse the length of the arena(mounted or not) or dismissing the risk of injury as baseless 'concerns' or substituting swinging its rump around after one dismounts, I am not going to be drawn further into that discussion.