@Thalatta You are right - will remove that constraint (also use captured buildings as a quarry). Will also change the refunding stone and metal (50% each) wood (30%).
While modifying the mod, I changed the "delete" function of everything: a unit being deleted (killed by its "owner") looses health over time (10s) until it dies (same es when being attacked), as well as any structure/siege/ships being deleted.
Here is the latest version 1.4.0 with that logic (I know there is still a way to go).
recover-resources.zip
README.md
Updated to 1.3.0 (see top of this thread)
Extended editing capability
Analyze tab lists also treasures and relics if any
Re-arranged section on the analyze and edit tabs fo rimproved readability.