If you have a place to do so at no cost to you, charge them the costs for removing and transporting in both directions. they may be long term tenants if they're that committed to their own appliances, so if in your shoes I'd try and work it out

Not too familiar with CA but believe it’ll be impossible to build multiple ADUs on one lot in San Diego  No, it is possible to build multiple units if you are in a special transportation area. 

“Michigan is the automotive R&D capital of the world and Detroit is uniquely positioned to leapfrog other urban cores to explore the role transportation can play in revitalizing cities.”The Motor City's historic strength in manufacturing is enabling it to become the center for the future of the automotive industry."

Whelton and his team discovered eleven PEX-related contaminants in the plumbing system: one, toluene, was regulated, and several were unregulated, including resin solvents, manufacturing aides, initiator degradation products, and antioxidant degradation products.For 30 days, the team monitored new PEX pipes, both with disinfectant (chlorine) and without disinfectant, for water chemical and odor quality.

Tenants will be more attracted to properties that are conveniently located near public transportation, major highways, and popular destinations such as shopping centers, schools, and entertainment venues.

Charlotte is a not a very walkable city but there is a strong consumer preference for areas that have establishments (bars, restaurants, tennis courts, parks, etc.) or public transportation nearby and within walking distance.  

Very different vibes but both have great transportation and amenities.

Raleigh has seen consistent economic growth over the past decade, attracting new businesses and developments to the area.Infrastructure development and transportation improvements have been a focus in Raleigh during the 2010-2020 period.

And it's not too difficult to find tenants if you price your unit correct and are in a good location next to public transportation etc.

I live in Jersey City and think that the public transportation is a bit more accessible here than in Union City.