First of all, thanks a lot for this plugin!
In the documentation, you state that "Anti Offline Raid determines who owns a structure based on who built it". Since bases are often built by more than one player working together, I'm unsure about how the plugin determines who is the original builder (or who owns the base, as you put it). I can think of 3 possibilities:
1 - The player who placed the first foundation.
2 - The player who placed the tool cupboard.
3 - The player who first authorized on the tool cupboard.