In essence, he has $45,000 annually in perpetuity that increase yearly in perpetuity all while property appreciates indefinitely. 

In that instance part of the tax is deferred indefinitely using the 1031 exchange. 

Also, at age 59.5 when you start to pull that money out, you will pay all your gains as ordinary income.When investing in real estate, it is possible to defer your taxable gains indefinitely, and when you die your heirs inherit the property at a stepped-up basis so nobody ever pays the tax.  

You can still do a 1031 exchange at sale to indefinitely delay the taxes.

Curious as to why you don't choose to do a cash out refi instead to still pull the equity out but keep the properties indefinitely.

The plan would be to then cash out refi and repeat (BRRR) indefinitely without needing much, if any, of my own cash.

I love it and use it, and it CAN be done indefinitely, but as scale increases other methods become more ideal

Living with friend in the same unit I could do indefinitely though. 

We extended multiple options, offering you the choice to either cancel or indefinitely pause the account, all while retaining access to the program.

An additional pro is the idea that the taxes can be (essentially) indefinitely deferred through 1031 exchanges.