The reason I ask about this is that I love the vacation STR strategy, but I know nothing about top-producing vacation markets and what is achievable.

I have no real expertise here though, although I have been a court mediator and am used to helping people lay out motivations, wants, needs.

The fact the commission isn't your primary motivation will help you stand out amongst even the most experienced agents. 

I'm selling a SFH in California to a motivated seller w/o using a broker.

If you have an opportunity to confidently achieve a rate of return in excess of the interest rate on your debt, then you should maybe not ignore the investment opportunity just for the sake of paying down some debts. 

With a 10% down loan you can still achieve 50%+ CoC in both of those markets.

Brokers and Agents can be easily motivated when the state starts looking into their business.If none of that works, then suck it up and change it once this lease ends.Your offer to purchase should include a requirement that they provide all documentation and agree to sign an estoppel certificate (also called estoppel form or agreement).

If your goal is to achieve greater cash flow, go with Airbnb hands down.

Generally speaking, the sponsor would decide to refinance and hold on to the property if they’re achieving high cashflow that they don’t want to let go of.

And when you manually sift through the rental data you can screen out the slop which invests time to achieve maximum accuracy.To evaluate for a single property address what I would do is go to realtor.com (which directly sources from the MLS), hit the rent tab, put the county of the property you're evaluating, and go to map view for a zillow-like view of what rentals are actually listed at what rent price.