I have found temporary renters from real estate agents who have clients waiting on a house closing and need real short term housing.

Either from a temporary (2-1 or 3-2-1 buy-downs) or a permanent rate buy-down.

The difference I can see with a rv park vs the tiny homes is a rv parks income is based on temporary lot rentals while a tiny home is permanent, if you talked about a tiny home that is mobile, it is virtually a glorified trailer.I don't think either make a dramatic impact on real estate, if anything air BnB in a neighborhood may hurt the areas pricing due to people who want do not want new occupants ever couple of days.

I realize both of these freezes shouldn't of happened for new construction, but it seems the builder fixed the temporary issue.  

My general plan would be to utilize a 5, 7 or 10yr ARM for the temporary lower interest rate and then sell/1031 or refi and lock in a lower fixed rate based on market conditions at that time.My questions are, does this seem like a sound strategy and, while I have a general understanding of how the 3/5/7/10yr ARMs work, are there major or hidden drawbacks to be concerned about when financing with an ARM?

I would say that justifies putting them up in temporary accommodations.Talk to your tenant and explain the situation.

The best tenants accept your otherwise nice property and see themselves as temporary and not that invested.

the future side of this is still an unknown quantity so its a risk that should be evaluated carefully.There are also several bills currently proposed in WA legislature which are likely to pass in some form or other which will substantially affect your situation - look at SB 5139 - "temporary" rent control   and SB 5160 - extending COVID protections for 2 YEARS past end of declared emergency,   payment plans based on "tenants ability to pay"  and blocking use of eviction and payment history in tenant screening  (!!!!) 

Just explain the temporary fix to potential tenants and even show them the new window invoice.

Hey Evan, If you are looking to purchase a home right now, I would ONLY consider the 2-1 Temporary Rate Buy-Down option, using seller credits to do that.