Better yet cash out refi? 

My main concern is the limited cash I have available for the down payment and renovation costs.

Always have a cash reserve on hand, maybe twice what you think you'll need.  

Finally, other tax deferral strategies prevent you from getting immediate cash, and your stated goal was to get cash for a down payment.Either this firm does not understand what you're hoping to accomplish or they are not being straightforward with their promises to you.

Regardless of your FICO, you will need cash money to be able to invest in holdable real estate.  

Do you think the curbless is worth the extra work and planning required?

In 3 years I’ve doubled my investment through sweat equity, and when I reached 10 doors I was able to retire my parents with the cash flow.

If it doesn’t cash flow in this scenario then it was a bad deal to begin with.

Are you saying you will actually need to possess the 20% difference in cash to bring to the first mortgage closing?

Getting those properties for pennies on the dollar, renovating them so they can withstand another 100 years, and fully furnishing them at a 30 day minimum is giving off some solid cash flow!