Hows the occupancy been?  

I assume your Borrowers are individuals who lived in the property and owner occupants generally pay a lower interest rate. 

When analysing an Airbnb property how can I confirm the owners claims of past occupancy? 

I started by looking at typical vacation destinations (popular beach/mountain towns), but after researching occupancy rates on AirDNA, I was surprised to see that occupancy rates in my hometown area (an ordinary suburb of Dallas) are just as high or higher than those in many major tourist areas.

I closed a smaller apartment deal (1998 build $70,000 median HHI area solid property condition 100% occupancy rents $100 below current market with no fix up located in a growth market - rated #1 emerging MF market for 2022) a few weeks ago and I used a 6% exit cap for a five year hold.

Not sure what the short-term rental market is like in CT Beach areas, in terms of cash flow, regulation, saturation, occupancy /off season opportunities etc.

It might be worth offering the tenant $5-$10k to move out with 30-60 days notice so you can sell to an owner occupant.

But the real way is to take the GPR, which is full occupancy at market rates, and then apply a vacancy factor.An easier way to think about it is: items that should NOT be in NOI.  

And what is your occupancy rate?

Unless you have four completely separate water lines, 4 hot water heaters, etc. then your best bet for sub billing is splitting based based on unit sizes or number of occupants.