I have used two companies, and while they are both more expensive than regular insurance, they have extra coverage that is specific to STRs.  

-------------------------------------------I am involved in a construction project which requires a Builder’s Risk policy/coverage…something off the beaten track for most people.

The cheapest is not the best, you don't want to lack coverage and be left with a high deductible. 

A DSCR loan (Debt Service Coverage Ratio) is another option that offers low rates, as these loans are based on the potential rental income of the property, However they are for investment properties only.

We have a handful of properties in the cape coral area that we're trying to find cheaper insurance coverage for.

-When you are out of town, who is your backup for coverage, for both maintenance and also general questions?

At the same time no matter how much excess insurance coverage you obtain, there will always be a policy exception for gross negligence and even negligence will likely be covered only under reservations of rights meaning the carrier can opt not to provide coverage. 

Some of the best rates and coverage that I've found is through Obie Insurance. 

Nashville is a fantastic area for both, with strong rental demand and plenty of opportunities for single-family and multi-family investments.I specialize in DSCR loans (Debt Service Coverage Ratio), which could be a perfect fit for your buy-and-hold goals, especially if you're planning to grow your portfolio.

We have a handful of properties in the cape coral area that we're trying to find cheaper insurance coverage for.