Or maybe you find a property that has a basement or ADU that you live in, and you can rent out the rest of the house to a family.

Paid 20% my own cash and had the bank take the rest.

ADU to increase value and cash flow and then refinance it. or Find a home that is zoned for 2 or 3 units that is 1 home currently: and add the rest and then refi out and get a large portion of your money back. 

Would it make sense to refinance and cash out to pay off the loan @2.75% and use the rest of the cash to purchase a rental?

I flirt with the idea of cashing out here in Los Angeles California and buying a primary cash in Tennessee (tax break and second amendment friendly) and then use the rest of the cash to invest in rental properties.Some things that cross my mind. 

Maybe try to buy 3 doors and save the rest for reserves (CAPEX, maintenance, vacancy, etc.)

We got pretty lucky/blessed that the rest of the house isn't like that. 

The rest of RE is sheetrock, paint, and flooring.  

I don't think vacancy, repairs, maintenance, etc. has factored into the equations yet.Priniciple, Insurance, Taxes, and Interest on a $307,500 loan should come out to a few shades under $2,000/month, I think that he is counting the rest as cash flow.

I own a skip tracing company and if you're offering JV in exchange for services I would be interested to hear what the rest of your acquisitions process looks like.