^I totally hear you, it's a lot to think about!
I feel like we're in fairly similar situations, at least in terms of where our horses are in life. I see Gator losing muscle mass, and see him dropping weight as a result. But is it worth the stress of a move?
On top of that, I know that I'm not in the condition to do the type of riding to put on muscle and build his top line; I'm not in a position to ride period.
But one thing you do have going for you, I think, is what a concerned and contentious owner you are. You are putting so much thought into this and really appear to be considering the pros and cons of all your options. Izzy is so lucky to have you as an owner!
I like, too, how you say your barn is willing to make changes and hear out your concerns. That's a luxury so many don't have!
How do you feel about some more high calorie options? Do you think the staff would be willing to feed something outside of their program if it was provided?