Most counties/states will recognize that the park has been grandfathered.  

Washington State does not recognize Series LLC.  

I own three duplexes in San Antonio and all of them have two mailing addresses (2 different street numbers) but bexar county only recognizes the "official" one that it was platted under. 

St Louis is a block by block market (to a degree that often surprises my out of state investors) but there are lots of great opportunities if you do your due diligence and recognize there's an important reason the seller is trying to unload their property.

Florida doesn't have state tax but most other states do so you'll need to plan for that when moving your property out of FL.PA doesn't recognize 1031 at the state level so if you 1031 into PA and later sell you will not be able to defer the state capital gain.

One downside to Series LLC is that not all other states will recognize the series structure.  

The major thing I'm seeing is that nationally recognized tenants, such as fast food chains, pharmacies, dollar stores and regional grocery chains don't really yield a cap over 5% or don't have a lease more than 5 years. 

Also recognize the supply risk for these areas with apartment/condo developments on the rise. 

Six months of inventory is usually recognized as the equilibrium point between a buyers/sellers market. 

I think he (or she) needs to recognize they are stuck and needs to be willing to take a loss.