@Belinda Fello- Usually, when you rent a property that has an HOA, you have a term in your lease that requires the tenant to comply with any rules or regulations of the HOA. 

I understand each city/county may have their own permitting requirements, fees, regulations, etc. but I'm wondering how people are making any return on their investment if it maxes out at 90 day rental.

In making this determination, the enforcement agency shall consult with the entity responsible for enforcement of building standards and other regulations of the State Fire Marshal pursuant to Section 13146.(4) The enforcement agency shall not approve any applications pursuant to this section on or after January 1, 2030.

Are there any local regulations or processes that are particularly tricky to navigate?

The City does not currently have regulations or allowances for land use known as “short-term rental.”

A heavily regulated market.

If you are in a metro area, I would always make sure it works as a LTR as a worst case scenario that regulation shifts.

New airbnb regulations obviously, but anything else? 

Personal residences or properties primarily held for personal use typically don't qualify for a 1031 exchange.Understanding state-specific regulations for like-kind exchanges is crucial.

Lastly, don't overlook any local regulations or HOA restrictions if any.