@Waverly Rennie  I understand the buyers are cash buyers but that's for a finish product... who puts up the construction money.. your talking a significant sum. 

I would not use the product in a higher end flip or rental.

(I'm not revealing the name of my software - or promoting it - so that I don't violate forum policies or appear to be promoting my product.

We have sold only a few products like this several years ago but the investment after about 9 months would turn into a nightmare for the investor.  

But I also have always bought turnkey, so the only due diligence I've needed to do was verifying the provider and the product and property itself.

A blanket mortgage is not a product offered by Fannie/Freddie and is less desirable for most investors.Several friends of mine who own 50-200+ SFR rentals have successfully found small regional business banks willing to lender based in the NOI and cash flow of their properties. 

@Mike Pauze if you are looking for a renovation style loan, search here for Alex Bekeza...he works with investors and is active on BPIt's important to define the loan product up front...some conventional lenders may not have the product you are after.

Use 10%/20%/30%/50% market declines as an example. 

I would reach out to a couple more lenders with your exact issue and let them know what you found about the Fannie Mae product being more lenient specifically and see if they will look into it for you.

Really, their jobs are the same sell you a product and make a percentage.