Anyone aware of the ins and outs of how Fannie Mae-backed conventional lenders count income from Airbnbs?

If the assessor doesn't count the sqft then that fact will come out during the escrow process and could sink the deal. 

Focus on the fundamentals of the real estate and stop chasing an arbitrary door count.

I would have $277 which is not enough in small unit count.  

And the appreciation in Cleveland was almost non-existent until the past few years, so I wouldn't count on big gains over time.You also have to remember things change over time.

For example, I can get up-to-date pictures of a property (with time stamp on it) for as low as 10$ in 24 hours, most of the time it is more expensive to grab your car and go there in person if you also count your time invested. there is a great book called "long-distance real estate investing" by David Green (you can find it in BP book store or on Amazon) which goes over a lot of those services and find solutions to long distancing investing.

I have been watching the DOM on most of these and midway through 2023 the DOM are continuously counting up. 

THAT'S what counts.

I can't count how many times lenders try to assign a percentage of ownership to a Trustee when numerous attorneys have explained to them that it doesn't work that way, etc...

For me when I'm estimating rental income I start by looking at the area for active listings <40 days old with similar characteristics to the home you're looking at purchasing (trying to find same bed/bath count, and same amenities like in CO homes with a fenced yard do very well because everyone has a dog).