Depends on where you are and what you are doing. If you are working somewhere, that state's registration laws tend to have precedence. Many states have a very short fuse for local vehicle registration if you reside and work there (no matter what you want to say about where you "live"). So in this case, it is probably up to California and how they want to treat a long term visitor camp host vs a working in California RV park employee.
Why would someone register a vehicle in Kansas (which is expensive and procedurally a major pain) if it could be registered in Missouri? People who reside in Kansas and work in Missouri or Oklahoma jump through hoops to register out of state.
