It was more expensive then say a VA or canned product, but that is what I was comfortable with.

The return metrics really vary by product type.

Work on that end..the product.

Ultimately, recognized that notes aren't sold by geographic packaging like off-the-shelf products.

It takes money to create and run a great product like BP

I helped a client in NY buy a similer situation a couple months back. i pretty much just printed off a list of 20 or so local banks called and asked if they had a portfolio product for this type of thing. 3-4 did and the rest told me it was impossible.

This could be in the form of local bank that houses their own commercial loans, acquisition lenders who also have long-term buy-n-hold products, DSCR loans, or going through a mortgage broker who can hunt down this product if you can't find it on your own. 

I would ask brokers here on biggerpockets and see if some carry in-house lending products or have other suggestions.

If you are looking for a loan product that the lender is not offering then you won't get the loan.

There are also opportunities to buy a single family residence home that has an ADU that you can buy with 0% down products (contact @Grant Schroeder).