In my market the valuation with f/f non commercial financing is typically lower than the hands off cost of adding the ADU.  

The upper east side is still beautiful right on the lake, but many of the other districts have tapered off when the big jobs left. 

They drop it off at the dump area.

Just so you know, Vrbo and Airbnb will not allow you to receive an inquiry through their platforms, and then take the booking off-platform, they want their cut of the money. 

I would definitely start off renting most units as LTR and slowly renovate and furnish units to do MTR, having a mix of both. 

The reason I say this is that with a 5+ unit a lender will evaluate based on NOI and a cap rate, so adding a 5th unit COULD (or could not) substantially increase the value of the building and make it worthwhile to refinance and pay off the existing loan (that is tied to the "old" quad) anyway.

Listen to the audiobook “The One Thing” to help prioritize your time and maximize your outcomes.The cash flow may get wiped out but the tenants are still paying off the mortgages and rents will still continue to rise, so it’s not all bad!

DSCR loans are based off of down payment, credit score and either actual or market rents so it helps to supercharge an investor's real estate goals and net worth.

Impressive investment strategy you've been pulling off! 

Since my friend lived there for at least 2 out the past 5 years, he qualifies for section 121 where he can write off $250k profit from the sale of a home.