Cross collateral is the easiest way to get a situation into NMD. 

@Lisa Hill in my experience, dealing with QOZ transactions is more for developers and heavy repositioning.

Sellers require a lot less work and are far more likely to result in a successful transaction and a commission check, whereas buyers will take up a ton of your time and a large percentage of them will never go through with it. 

Also, there is no need for an agent in this transaction, and no legal need for an attorney in NY, you should have an attorney and definitely a title company.

Echoing Greg again, you will certainly want to engage an attorney to make sure that you aren't crossing any lines with the residential component of the lease.

Or is one deal going to die mid-transaction if you go under contract on both?

The following language is in the Standard Illinois Residential Real Estate Contract: CASH TRANSACTION, MORTGAGE ALLOWED: If this selection is made, Buyer will pay at closing,in the form of “Good Funds,” the Balance Due at Closing.

I’m a new investor and just this week, after about a year and a half of saving and learning, have just put my first property under contract (fingers crossed)!

I got A LOT of training before I paid in my first 'company dollar' from commission split on my first closed transaction. 

Long term hold for (fingers crossed) equity gain along with good cash flow.