Detailed analysis? When we don't properly understand the mechanics? Not likely going to happen. I was just going to put up a few sentences about the importance of decay, the trouble with that mechanic, and what claims do to prevent it.
If someone has a screenshot of a decayed lean-to or other building or can make one to demonstrate the discoloration, it would be helpful. Otherwise, it might take a few weeks to get a demo picture. (Suppose I could "decay" a lean-to myself as items discolor on damage no matter the source.)