How to use pgloader to transfer sqlite to postgres with table name in Uppercase
In SQLite, table names always are case-insensitive (even when quoted).

In PostgreSQL, unquoted identifiers are folded to lower case, but then the search for the table is done case-sensitively. So the only way to get the same behaviour as in SQLite queries is to use unquoted names, which implies that the actual names must be lower case.
In other words: the table name must be testname in order for a query like SELECT * FROM TestName to work correctly.