I've seen this tried during HEA, and it didn't go well.
Let me open with, I'm completely content to sit, if everyone sits, it's easier, I don't mind it at all. I'm not going to sit happily if others in front of me are standing, it's not about getting my way, it's about actually seeing things. I'm short. Last time we saw HEA in July the Cast Member was insisting we sit. Making a scene at people that balked at it. So we all sat, the garden section immediately in front of us, across the walkway (fireworks dessert party) was not instructed to sit, or didn't listen. None of us could see anything. One by one, as the show started, we stood up, meekly at first and then with greater irritation. Eventually people behind us make a fit instead of standing, which I suppose is considered more correct, they wanted to obey the rules more than see the show they'd paid extra specifically to see. I don't get that. However, with their complaining, the CM swooped in and insisted we sit. I missed most of the show. If everyone had sat, no problem, if everyone had stood, no problem. The mix only screws those that choose to play nice, and because our culture is to not play nice if it means compromising your wants at all, anyone that isn't fully committed to sitting and not seeing is the bad guy.
It's kind of annoying.
Matt