It's also possible to qualify the name in the ON CONFLICT clause, although I think you have to parenthesize it to do so:
... ON CONFLICT (("Lockers"."Uuid"))
This really needs to be confirmed and, if so, better documented on the INSERT page, since adding a schema to the index_column_name does not intuitively turn it into an index_expression which is what the syntax diagram says requires an extra pair of parentheses.
