I think both methods can work.

Id work the DSCR route and Use the stacking method......1>2>4>8>16>32>64but but make each one of those Duplexes and not actual doors......1 duplex, 2 duplexes, 4 Duplexes, 8 Duplexes.

Application screening is method of determining risk.2.

I have gained 100% returns on money invested with this method overlaid in a recoverable down market.   

However, there are structures and methods that might allow such a transfer without jeopardizing the 1031 exchange, but they require careful planning and legal guidance.

The intention for this investment is to use the Brrrr method.

That said, the GC I am looking to use has told me it would cost me more to build a duplex vs two sfh's (same sqft) r/t firewalls etc when it comes to additional steps for adjoined units.

You posted this thread, so you have already started.Just like @Jonathan Greene mentioned, don't chase the quickest and easiest method to wealth.

Others employ a BRRRR method or do wholesale deals/flips to have cash to invest long term. 

But there is virtually nothing for a fix and flip type borrower or a BRRR method borrower.