For example, we need proof of renters insurance and proof they put electricity in their name.So, it seems odd that you are accepted but they keep wanting more information. 

Electric: is the easiest to split, but may require holes cut in walls to separate the units.Gas: gas lines aren't as flexible as wires, but it can usually be done affordably.Water: most cities will NOT install additional water meters on a property.

Quote from @Jeremy Dugan: I am a US Air Force and Massachusetts Air National Guard veteran with 20-years of experience as a military Civil Engineer.

It was a huge investment, but it cut the electricity cost by the full 2K per/mo all summer.

However, these properties generally have a lot of land improvements that qualify as well as certain portions of electrical, mechanical and plumbing that can qualify.

The limit on scaling is your deal flow (mine never was that good) and time it takes to perform the value add (I got fairly quick for example, my last rehab did all new plumbing, electrical, and flooring.  

Engineered cost segregation studies is an area in which many people have a lot of questions about.

Will - I work with CSSI, the premier company providing engineering based cost segregation studies in the U.S. 

-Both homes have new windows, kitchens, baths, flooring, electric, solar, landscaping, you name it, with custom tile and woodwork. 

I would suggest one or both of you go talk to a Civil Engineer and ask if they can see a way to accomplish what you are trying to do.