I don't know of a legal prohibition on it, but you would need to find a settlement company willing to accept it.

In my state, rentals less than 30 days are not regulated by the Real Estate commission.I don't think any of these short-term rental platforms explicitly prohibit arbitrage, but I wish they would.

This goes along with some exclusive use/prohibited uses.  

Non-recourse lendershttps://www.biggerpockets.com/member-blogs/2810/50272-list-of-non-recourse-lenders-for-self-directged-ira-and-401kSolo 401khttps://www.biggerpockets.com/member-blogs/2810/21298-solo-401k-advantagesSdira self directed ira https://www.biggerpockets.com/member-blogs/2810/blog_posts/28450-real-estate-iraProhibited Transactionshttps://www.biggerpockets.com/member-blogs/2810/44738-prohibited-transactions-for-a-self-directed-solo-401k-or-checkbook-iraDisqualified Personhttps://www.biggerpockets.com/member-blogs/2810/47960-disqualified-person-in-a-self-directed-ira-or-401k

Most ADUs are ground up and are cost prohibitive. you need to contract dwelling units under 1000 sq ft at $250 per square foot to make the numbers work as a builder in columbus. the cost of an adu and rezoning I'd pass on this one.

A quick synopsis: We got our zoning approved through the city, we then had to get a variance because we want to run an 8 bed facility but the International Building Code would have had that be a "Commercial" property and would've needed to be compliant with all of the ANSI requirements like having an accessible main floor bathroom and 2 accessible main floor bedrooms, this would've been cost prohibitive to us.

Homeowner's and flood insurance can be considerably lower than in other coastal areas, especially in comparison to States with prohibitive property insurance markets such as Florida.

It may be state specific, for instance Texas prohibits naming the owner along with LLC I think???

Anything above 10+ units is generally a minimum of 30-35% down but the rates at present are prohibitive.

As long as the military doesn't have any prohibition on you having a house/apartment as your "residence", then I don't see any reason you couldn't.