Considering this tenant is most probably judgement proof, who would you go after in this situation?

Proof of Payment - The industry standard of documenting a mortgage that does not report on your credit is with a "verification of mortgage" (VOM) form. 

Since there is no record, there is no proof from the city that things weren't like that before.

Having hundreds of hours managing a myriad of STRs you really get to learn and get a pulse on what makes a property successful, how to mistake proof a property, and what it takes to keep them performing optimally. 

He is the living proof of that.

But I have been looking into splitting the duplex into two condos (yes I know it is a lot of work) and I could probably get 325-350k for each, netting me 650-700k.Number:* Mortgage interest 2.5%* Mortgage principle 240k* PITI $2100/month* Rent 2200/month (current tenant on a two year lease)* Potential rent on my side $2400/month * 100k HELOC at 11% (fixed) (not currently being used)* est additional cost to split the dueplex 75-100k (conservative, probably less)     *new siding 30k (just put on a new roof this year)     *legal 10-15k     *fire proofing 15k     * 15-40k for stuff I am not aware of or underestimated on* some of the appreciation is external from the home     *big grocery store put in 3min away     * newly paved road in front of my house     *a building that was falling down across the street has been torn down          * Still a vacant lot with the foundation exposed and fencing around it (so more local improvements are on the way)Part of me wants to take the money and run but man I love that 2.5% interest rate and the $2000/month cash flow (including taxes and capx)I have thought about 1031 exchanging into more rentals, but I would like to pivot into storage units.

There is a PAC coming and proof of other markets fighting similar situations.

Finally, I pulled down the proof of insurance from their website portable.

The pro of a feeder fund is if you trust your FF GP and they are well connected, they can be performing due diligence on multiple operators.  

Used to be a commercial appraiser and thats how I did it for reports I was getting paid to write because we had to show proof the comp was confirmed and Costar provides that service.