Speaking of corporate landlords, this is a very interesting resource mapping the top 100 business entity owners in San Francisco: https://corporate-owners-sf.netlify.com/
And as long as we’re talking maps, two more:
The Anti-Eviction Mapping Project’s map of San Francisco evictions: https://www.antievictionmap.com/evictions#/sf-evictions-1/
The San Francisco Rent Board’s map of buyouts: https://data.sfgov.org/Housing-and-Buildings/Map-of-Buyout-Agreements/aa2m-ehxd/