So, you can't get a conforming residential loan anyway.You could go with your other routes, but that would just tie up their credit service ability. 

@Brendan ChaseJust realize that a conforming non owner occupied residential loan is still more expensive than a owner occupied loan.

You have to provide the financing and it's not a conforming product. 

It sounds like this most likely won’t apply, but if you plan on pulling cash out via a cash out refi, you may run into headaches with conforming loans.

Is your basement conforming and was therefore counted in the square footage? 

One of the problems with creating a web app, is that your vendors will have to conform to using it (which some may simply not want to), or worse, they will say they are going to, but do not and your have even worse communication loop than you had before. 

Pre-COVID-19 you can't get conforming loan for less than $50k. 

Permitting can have issues or restrictions based on the city or county and whether the structure was conforming or not.

Just remember that a legal entity is not eligible for conforming residential loans. 

Remember, conforming loan criteria can be one thing, but what a lender does to originate a loan can be that criteria or tighter as I have found by experience.