I am of the opinion that cash flow underwriting comes second, after first nailing the long term deal fundamentals, how strong is the equity upside and market generally speaking. 

Thank you for your reply I will send you an e-mail

You can however, write off the other unit as a rental on a Schedule E.

.: Quote from @Albert Hepp: I think the fundamental question buyers, sellers, and agents have to answer, is why do US consumers pay three times as much in commissions (5-6%) as other developed countries(1.5-2%)?

Here is a fundamental flaw to Sub2, that this situation seems to exemplify. 

E Equity, how much of the home will you own on day one.  

I did a quick check in SLC and while I couldn't find a duplex at that price point and what I did find was pretty far out from downtown, but would something like this: https://www.realtor.com/realestateandhomes-detail/141-E-Nort... be of general interest?

I'm an investor here in Columbus OH myself and have seen the city's solid and steady growth with strong economic fundamentals driving the market like major companies moving here (Meta, Intel, Google, Amazon, etc), job growth, and population growth.

Rental income and expenses, such as mortgage interest, property taxes, repairs, and depreciation, can be reported on Schedule E of your personal tax return, regardless of ownership structure. 

If you provide any kind of substantial services like catering, car service, etc you will change you tax situation and no longer can file under Schedule E.