If your goal is less required documentation, DSCR is likely your best bet as most everyone as mentioned, possibly a bank statement program depending on your job structure. 

Large gifts, including real estate, may benefit from structuring around this limitation.

Structuring a 203(k) loan for your partnership involves some creative thinking, but it’s definitely worth exploring.

The book is useful for understanding how to structure deals, assess risks, and think like a lender, rather than just an investor.Pair this with engaging in forums like this one and attending local meetups to put what you learn into practice.

They need analyze  the property, the deal structure, and the sponsor. 

Differentiate between different risks , economic risk, structure risk, incentive risk, etc.5.

Plumbing is historically one of the most difficult things to fight since age and the structure matter so much and it is nearly impossible to pinpoint one issue that caused the damage. 

As far as refinancing, you can either do a conventional loan where they use your debt to income / DTI to qualify or you can use a DSCR loan which structures the loan off of the rent versus income ratio.More info on DSCR loans: DSCR loans won't use your income to underwrite the loan. 

Add in many/most jurisdictions are (I believe incorrectly applying the law) mandating the existing structure be rent controlled (assuming it is over 15 years old).The reality is virtually all RE investments will do better than adding an ADU.  

I’m currently looking into the best ways to structure guest payment flows to ensure legal compliance (that may restrict non-licensed property managers from collecting rent directly) and seamless operations.