wow, surprised to hear you sell so much!

yup stayed in the land bizz till late 80s and was in land and timber in the 90s and of course from middle 90s to now I have developed about 500 to 600 lots for homes.And all the while I bought land to flip..

STR stays STR.

Your approach to finishing the basements in order to extend the number of years a tenant stays in that unit makes perfect sense!

Less waste, more controlled environment, less surprises. 

Make sure to provide clear disclosures to the seller about the risks involved, especially regarding the existing mortgage staying in their name.Insurance Considerations – You’ll need to work with an insurance agent who understands sub-to deals, as the lender might require a policy that keeps the seller as the named insured.Due-On-Sale Clause – While banks rarely call loans due, it’s still a possibility.

PPMG claims "...an average length of stay of 5.3 years

That said, staying on top of losses and basis is important and worth the cost of a CPA.

Not necessarily insurance company stays but simply people looking to relocate for a few months and try it out.

EDUCATE YOURSELF - yes, it will take time, but will lead to a selection that better meets your expectations & avoids potentially costly surprises!