I don't think insuring a building for more then it's worth is an issue. You pay a higher premium. If there is a claim the insurance company will pay what they think is fair, not what you claim the building is worth. We all know that insurance companies do not over pay a claim!
If I was Trump, I would sue Palm Beach County for too high of a tax bill. Use the Judge's ruling as proof that Mar-A-Lago is over valued. Next sue NYC for property taxes too high! After all you have the Judge's valuation!
“”After all you have the Judge’s valuation!””
All good ideas - YES.