mate, unless your hand is really really tiny.... he could go for the 48 inch cage.
My Panthers are a tad smaller than that, and they are gonna get moved over in the summer when I can just get two cages at once ( you hear that LLL reptile, im asking for a summer sale price!!!!!

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supp schedule seems fine with the d3 changes your making.
you said its hard not rubbery? mmmmmm perhaps he did have a nasty fall and hurt himself, like I said before - while falling is a sign of MBD its not an absolute, sometimes they just misjudge distances and fall like a potato sack.
from your pictures though I would say he appears pretty healthy - minus the taking forever to shed. I would mist more often and consider purchasing a humidity meter to make sure the humidity is just right.
On a personal note, in winters it takes my panthers a while longer to shed because of lower humidity, but two trash bags pretty much solved the issue, of course 3-4 mistings daily of warm water for 3-5 mins helps as well

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In summer though Cali gets pretty sticky, and I don't think shedding will be an issue for them then.
Best of luck with your guy though, hese looking good