I bought two pairs of the DiD boots sometime before that photo for Han and an Imperial officer. They're no longer on that figure, but I just checked both pairs and they're fine.
If you're worried about cracking and flaking then put as little stress on them as possible - don't force feet into them, but remove the feet, fill the boots with cotton or tissue and then drop the legs into them.
didn't know they still making the boots after so many years.
for me i had to because i had to slip them under a pair of rubber guards, couldn't figure out any good way of doing it without bending it. i could heat up the rubber to make it stretchable but still i need some tubes so the boot upper won't bend while going in.