They do minimal at best verification of the data the applicant provides.

Assuming plans are needed to secure a permit.

I interpretttev @Alan Asriants statement different than you but agree it is not clear   He could be indicating pools, basements, sunrooms do not provide a means for an extra tenant.  

If you are familiar with this area, any further recommendations or resources you are willing to provide, I am super grateful. 

Hello AllI have a opportunity to purchase a 3 unit rental property. how should I structure the offer and what should be required in it.Does the seller provide a fee and clear Title with Title insurance, should the seller be required to evict the tenants before I purchase, what verifications or contingencies should i include. etc......ThanksJeff

An additional benefit of a detailed engineering-based Cost Segregation Study is that it can increase potential insurance premium savings as well as provide support for the property tax appeals process.

I'm just hoping someone with actual knowledge of it can provide some information that offers an alternate explanation.

And it doesn’t matter if it’s CA TX  ID AR or FL Subject To can be done SAFELY, out of state, too.More info at the link provided by Bigger Pockets, just below.

That's the opportunity.I also recommend engaging an 'investment focused' realtor (not the general residential ones) to guide you through the process and provide you with market intelligence. 

These reviews typically highlight:✔️Location✔️ Cleanliness✔️ Host communicationNice to have, but not enough to differentiate your property in a competitive market.A Raving Review Markets It goes beyond the basics and helps future guests see the one-of-a-kind experience that only your rental provides.