Thanks Tahoe, I'm not throwing in the towel by any means. Mostly just didn't want to overreact and cause even more damage. The only things I really lost (meaning no frags left) were the acrolandia and the Walt Disney. The home wrecker, rainbow loom, space invader, OG bounce, etc all survived and are back to growing.
I have a clove outbreak now and am going to start dosing the tank with fenbendazole to nip that in the bud. Once that's cleaned up I will get back to manicuring the tank and getting some new residents growing healthy and happy.
If I had to guess I'd say some alkalinity swings caused by the SPS to stop growing suddenly. They weren't showing damage, just stopped growing. Then the alk and ca did their thing and as much as I tried to adjust I just ended up chasing my tail. Then I could see the recession beginning and started doing ~60g water changes weekly thinking enough of those would force the water to correct itself but nope. Couldn't get it stable so I simply stepped away for 6 months. Things are now growing. Weird.