As to your points about other methods such as 'investing in a private syndication' or the like imagine this; you can invest say 500K cash and make a 500K return over 5 years that you now owe say 200K in taxes on leaving you with 300K profit - *or* you could invest 500K from your ROTH IRA or SOLO, make a 500K return and owe NO taxes and net 500K profit - a 66% better return.

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.

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

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

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