I know this may be a bit of a stretch, but is there any chance of adding a feature where after a certain amount of time the ground will return to normal? As it is currently, especially on very old maps, it starts looking very nasty after a while, especially with walls causing the "scorched" texture everywhere...

Its great proposal but needs smart scheduling of the landscape restoration tasks in main cycle. And I have concerns about the balance of memory amount to save the data about scorched tiles and a reasonably long time to recover ground textures.

I have postponed this because some dummy realization will lead to unconditional spikes in CPU load.
Maybe one day :)