I considered doing a simple rate/term refi after the rehab was done, but with the ability to actually pull cash out of the deal on a cash out refi, making my cash-on-cash ROI an infinite amount, I decided to go this route.

Based on your assessment I'm not sure how to value the coverage needed because your idea leads to the thought that a person needs an infinite policy to be fully protected.

As K Marie said, you can buy subject to an infinite number of liens, but the question is do you want to.

(There are lots of assumptions but I think the likelihood of being in this range is >95%)I know this is not a "home run" investment but my cash on cash return is essentially infinite with a $0 down mortgage.

. :-)Build the plan and execute (It's an infinite OODA Loop)

Purchase price $45KRehab 47KARV 135KRents for $785-8004/3 single family c+ to BI can refinance it at 3.6% and take out 100K and have an infinite ROI, but it will only cash flow at $42.79 after property manager, vacancy & repair.

More costly, but infinitely faster/more competent. 

In some cases you may have technically infinite rate of return if you have no money in the deal. 

the advantage to buying "below market" is the possibility to refinance all your money out of the property and have an infinite return.  

I do think these guys will be able to buy it in time and I've loved them as tenants but my kindness isn't infinite :)