What is clear is he added a lot of value as evidenced by what he sold it for but that size rehab and adding an ADU was a lot of work.  

We need to repair a small portion of the roof in detached garage in multi-unit, in Evanston.

TIAA lot is going to depend on the value/loan size and whether the town in IN is going to be considered rural or not by DSCR lenders. 

I want to keep the property longterm since its a good rental and the interest rates unbeatable but I want to pull by 10K downpayment as well as renovation budget out of the property.Has anyone ever had any sucess refinancing a portion of the home while still keeping seller financing in place? 

Save for Your First InvestmentCommon Pitfalls to Avoid:Don't rush into deals without proper due diligence.Avoid over-leveraging or taking on too much debt.Be cautious of "get rich quick" schemes; successful real estate investing takes time.Don't neglect legal and regulatory considerations.Remember, everyone's journey is unique, and there's no one-size-fits-all approach.

When they calculate the financing for spec homes, a lot of times they can't accurately forecast this portion.

Some niches allow you to scale but you get negative momentum as you grow.My niche for the last few years has been small and medium-sized mobile home parks, I don't like RVs very much, I like to keep it simple.What other niches within the manufactured home space are you guys finding success?

That being said you are in a great situation with the size of your income.

NOI, and thus cap rate, feeds into how much of a down payment is required b/c it feeds into the "sizing" of the loan.Many asset classes, like apartments and offices, have less than ideal in place cap rates today, so you need 35% or 50% down to buy them (unlike a DTI-based home loan, your personal W2 income cannot be used to significantly offset).

Specifically, do mid-sized to small towns outside of big cities have sufficient rental demand for rent by the room?