As such I am going to find out in next few weeks (as I am converting one storage shed into an ADU studio) in Hayward (unincorporated county area)

Also like self storage.  

If it is far from the main property the best use might be as storage.    

@Anthony Taylor so if it won't be furnished definitely rent long term but remember you are taking on the additional costs of furniture storage.

Parking stalls, storage lockers, pantry and refer shelves, whatever you don't want to have to argue about.

@Logan M. thankfully no lost communities but I lost a storage facility in Panama City.

I'd like to execute as many flips as possible these next couple years in order to build my capital to then focus on commercial investments being Strip Malls, Storage Units, or Apartment Building/Complex.

Personally, I would invest in in numerous apartment, self storage, and MHP syndication deals.

When mini-storage sites go up, there is no guess work, they have done feasibility study and know exactly the market demand in the now, near future, long term, and they build to that.

Maybe self storage.