I decided to check some weird Inheritance interactions, and to not always be a guy who complains about bugs, I'm happy to report that all seems to be implemented correctly:
If you trash an Inherited Estate with Transmute, it's not yours when Transmute checks its types, so you only get a Gold.
When you gain an Inherited Estate with Ironworks and then trash it with Watchtower, it's not yours when Ironworks checks its types, so you only draw a card. If you have your Estate token on Fortress, the trashed Estate returns to your hand, becoming yours again, so in that case you draw a card and get +1 Action.
With your Estate token on Embargo, playing Throne Room + Estate only works once. I assume it's correct for all cards that trash themselves.
With your Estate token on Grand Market, you're able to buy an Estate even with Copper in Play.
Stonemason overpay doesn't let you gain Estates. I assume it's correct for all cards that gain Action cards.
Not checked: Trashing an Estate with Transmute while Possessed. Since it gets set aside, it's supposed to be yours again when checked by Transmute.