@Billy Britton I am sure there is an opportunity for someone who wants to take on the challenge of dealing with this type of tenant.

Hello, Was looking for feedback regarding  what type or when a master key setup makes sense to add to our portfolio of properties. 

There's a max of 4 units on this type of situation for primary residence though.

The course combined with my BP lurking has got me feeling quite confident with the real estate lingo, different types of loans, and the basic concepts. 

That being said, they are all going to be very specific to the type of property being purchased, financing used, rented, flipped, commercial, residential, etc. 

I haven't seen this advice given in the many posts asking about what type of returns new investors should realistically expect.

The downside is restrictive guidelines, a ton of paperwork, lack of flexibility.Commercial types of financing have pros that are flexibility in guidelines and structure you can do all sorts of stuff from substitution of collateral to partial lien releases on blanket commercial mortgages to cross collateralization and many others, less documentation than conventional financing products, use of debt coverage ratio (DCR) as opposed to Debt to income (DTI) and if you compare DCR to DTI the commercial lenders go up to 80% DTI since the reverse of 1.25x DCR is .80 or 80%.There are downsides to commercial financing and that is the convenants with in the mortgage note that can allow the lender to call the note so make sure to read all the definitions for what substantiates a "default," by the lender you'll be surprised by the definitions and language at times. 

Your cash flow in a recession would largely be dictated by your location and the type of traveler staying at your unit.

Personally, I would steer clear of this type of transaction. 

For instance my lender will do a loan for BRRRR type projects for 50/50 owners, 30yr AM, and very competitive rates, with zero seasoning. if you leave it in one individuals name, both title and debt, it'll be much harder for you to claim a vested interest.