The advantage Podio has over say Highrise, Salesforce, Top Performer etc... is the fact that it is basically infinitely customisable from its setup, lead capturing, integrations with other platforms, and automated workflows

This changes as the mortgage gets paid down or appreciation increases the value of the property.Other less professional investors will usually ignore equity and appreciation in order to create artificial cash flow and ROI returns higher than they actually are.In your example they will likley suggest your ROI is infinite and your positive cash flow is actually $250 higher than it really is.

Provided that each refi @ 70-75% ARV still leaves you with positive cash flow on each rental, THAT'S the concept of "infinite returns"! 

Sorry for the long intro and infinite questions.

REI is the only investment where you really don't have to spend any of your money...just use it an infinite number of times, and that is the main reason it trumps the stock market exponentially.  

If you put nothing down and made 10K that return IS infinite on YOUR investment, which is $0.

Well, technically any income with no money down equates to infinite returns.

I have found repeatedly that my "1% deals" have been far more profitable and infinitely fewer headaches than my "2% deals" ...

Lol, I'm all over place, but the possibilities seem infinite to me.

I have done BRRR on 2 properties and was able to get all cash out on both, when doing BRRR the CoC is infinite.