I totaled my first camper.
State Farm paid for it at current replacement value. No problems.
Originally, the camper was added to the truck policy at a cost of $15.00 for the rider.
Homeowners insurance covered it at home. Truck insurance covers it while on the truck. The rider covers it if, for example, I leave it somewhere like a state park and a tree branch falls on it or someone runs into it.
These are questions that one should ask their agent.
Having a homeowners policy is a foundation upon which other policies seem easier and cheaper to build.
Also of great importance is the insurance agent him/herself. An agent who is current on insurance law and keeps him/herself informed is VERY important.
Based on some of the comments about State Farm, I think that their agents may be better schooled and have higher requirements than other insurance company agents. YMMV