To get the limited liability protection, everything has to be under the LLC, eg title, mortgage, etc. this trips most people up since they don’t want to “pay” for the liability protection, ie the fact that you’ll need commercial loans since a legal entity doesn’t qualify for conforming residential loans.Don’t forget your insurance...Note, Unless you are investing with a non-spousal partner, the LLC has no accounting/tax benefits.

On the left is 2 nonconforming prewar buildings with 56 total units, on the right, on the same size plot, is 4 conforming houses (3 are Bayonne Boxes) with 8 units.

Most lenders sell the loans that they originate and therefore they have to conform to the buyer's standards. 

From house hacking, rent by the room, to creating non-conforming duplexes there are always opportunities to make a deal happen, even on the MLS.

Just realize that a legal entity needs commercial funding as it doesn’t qualify for cheaper conforming residential loans.Learn how to protect/maintain your corporate veil.This topic comes up daily.

The rates are almost identical because they are conforming.

When people dispute the units given on the zoning cert, water dept records is usually the first place they look into, especially for questionable "grandfathered in" units that's no longer conforming.

If you are going to go this route keep in mind the limits on conforming loans.

I'm also facing similar DTI concerns as you are for a conforming loan and am looking for a lender in that market that would be able to take the expected rent into account.  

Does it work to just install the Luan over top of them - ie. does it retain it's firmness / smoothless and not eventually conform to the irregularities underneath it as well?