The reason for the shoeing is for relief, not treatment. The vet, farrier, and barefoot trimmer all agree that it's best given our situation, which is that he is on HARD ground and it cannot be avoided. Ideally, he'd be in a stall with sand for support, but that's simply not an option. Given that he will be shipped to our new home in 6 weeks and enduring a 10-hour trailer ride, we're going to put him in shoes and keep him in them until we get to where we're going. Once there, we'll re-evaluate and hopefully go back to barefoot.
Luckily, the grass enemy is not a problem - we're moving to Las Vegas, so nothing even grows to snack on. As for as feed control goes, I couldn't ask for a better location haha.
My barefoot trimmer called and had a length discussion with me about what's going on and is completely on the same page with our treatment plan, the farrier I'm using, etc. And this is coming from a used-to-be-farrier turned barefoot trimmer that won't do shoes if at all possible - and it means she's giving up business for the sake of my horse. Moreover, she has a horse that has had laminitis so bad that he rotated and sank, which is 100 times worse than where Flash is at (per her words and having seen/done his feet only two weeks ago). However, with proper maintenance, he now does regular drill team practice and performance (not demanding at all, right?) and may go back to doing Limited Distance endurance rides once some other unrelated issues are cleared up. I feel lots better - with your stories and hers, it feels like a giant hug and everything will be fine :) I'll always have to be on top of his care and maintenance, but he'll be A-OK.