The good thing about Tacoma is that it allows non-resident Accessory Dwell Unit (ADU) without living in it.

One of the good things about Tacoma is that it allows non-owner occupied Accessory Dwell Unit (ADU). 

Upon reviewing the zoning documentation, I discovered that the property was a single family residence, with a permitted accessory dwelling, and a permitted business office.

By the way, instead of a duplex, you might be able to find a single-family home with an accessory dwelling unit to use as a rental.

I explain that on my condo, house and accessory dwelling unit alone here in Los Angeles will net approximately $100,000/year with 3% appreciation in 30 years.   

Besides this option, are you also open for a house hack (finish of a basement, Accessory dwell unit, mother-in-law, .....)If you are open for the two options, you will have more houses to choose from.Always open to more conversation over phone or coffee if that's helpful!