Price the stack before anything else. Transactional funding on a same-day double close is usually quoted as points on the loan amount, and on $1.85m even a couple of points is tens of thousands before fees. Add a second owner's policy, a second set of recording charges, and transfer tax. Transfer tax is the item that varies most, and it varies by state and sometimes by county, so get the actual figure from the title company in writing rather than working from a percentage someone quoted you. In a high transfer tax jurisdiction a $1.85m round trip can take a $110k spread down to something that doesn't justify the risk you're carrying in the middle.
The alternative structures each have a catch. Assigning an entity interest, where you hold the contract in an LLC and sell the membership interest instead of the contract, avoids the assignment clause on its face, but whether that's respected depends on the contract language and on how your state treats it, and some states have looked at exactly that pattern. That's an attorney question in the state of the property, not a forum question.
A straight fee agreement with the seller, where you're paid at closing for finding the buyer, can run into licensing rules, because getting compensated for procuring a buyer for someone else's property looks like brokerage in many states.
What I'd watch that you haven't raised: in a double close your name goes on a deed at $1.85m and out at $1.96m, and in states where prices are public your buyer's agent can pull both. Some buyers accept that. Some renegotiate hard the moment they see it. Ask your operator whether the end buyer has already been told the spread.
