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.

There is about 400 distinct in diverse real estate markets in the US.

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).