Take payment via Venmo and take the risk on yourself. 

There are a ton of neighborhoods and the boundaries are frequently not well defined and at times might feel arbitrary.

What benefit do you perceive you'll have by lending via an entity?

You could easily add 1-2 bedrooms within the existing square footage, maximizing your house hack and later on potentially rent out via Section 8 where the government pays you based on the bedroom count, not necessarily based on floor plan.

In future, assuming the 1031 sticks around (I tend to believe it will), our plan is to roll over from one syndication deal into the next, via 1031. 

If they don't voluntarily pay up via your lease, you are going to have to take them to court.

I'm willing to pay via venmo or paypal.

If I cannot finance it via F/F, I expect at least 10% reduction above the reduction I typically receive when I purchase an investment RE.  

In other words, if the contractor finishes the work 1 week earlier than scheduled (agreed to by both parties of course), and I give him back via the early finish bonus my exact daily cost, I can move on to the next investment that much faster so in the end, it is a net gain to me AND a net gain to the contractor.

Having rules and boundaries is the only way to keep a business from failing.