I believe the biggest obstacle you will face is the need to rely on a 3rd party builder for a 4 unit building.

Lots of BS excuses and finger-pointing at their hired out Accounting Team for this.My biggest concern now in terms of this one investment is that they are way over-leveraged and are in a position where they will need to refinance soon which will likely result in negative cashflow with interest rates where they are at.   

You will likely have to borrow through an LLC so just know that is an additional cost up front.The biggest thing, at least in my case, would be finding the multiple deals that work for you, that you can take down at the same time.

Job and population growth are some of the biggest factors for appreciation. 

The biggest difference with DSCRs is usually 1) prepayment penalties 2) more points 3) an affidavit that you cannot occupy the property 4) covenants and agreements regarding the requirements and rights of the lender to protect/preserve the collateral that may be more aggressive than Conventional.

So what your telling me is you would not take the advice of some random stranger to make the biggest financial decision of your life? 

What are your biggest issues that seem to keep coming up with inspections?

One of the biggest things I regret looking back on my career is not getting into multifamily sooner and thinking that I had to start in residential and then to slowly work up my unit count.

For me that would be the biggest consideration.

The biggest sticking point I see with those kinds of lenders is that they generally require experience - if you haven't done something like this before, then they will want someone who has to sign the note.