I can't exactly claim to be surprised. This is exactly what the farrier predicted would happen.
Sometime in the last two days, the small crack leading from Tristan's surgery hole to the abscess hole has become a large crack. As in, I can now see daylight through it and with pressure move the two parts separately. The toe has grown out enough that walking on it has pulled the crack wider. Ugh.
He does not seem sore, but obviously his hoof should not move like that. I would guess that increased movement would put him at risk of an even bigger crack. So he's back on complete stall rest, poor lad.
I will check in with the vet and the clinic in the morning, but I suspect our way forward is to keep him quiet and get his foot trimmed and a shoe put on as soon as possible - which could prove problematic, as the farrier may not be back from Florida for another few weeks...