> What happens when I’m allowed to view a column for some entities but not others?

Column-level rules are a DB design smell, because if some people have a reason to view a table that is coherent without a column, that suggests that you've got at least two different fact shapes communicated by the table that should be normalized into separate tables.

Each of those tables then needs appropriate RLS rules. Sometimes you do a join (OUTER on one side) of these tables, so that they look like one, and this also solves the combined row/column security challenge that comes up when you have the less normalized table.