I'm using the latest pgAdmin and notice that its "create database" GUI feature lacks the new "builtin" option of Postgres 17 for locale provider and related options like "C.UTF-8" so I could only create a database with the "builtin" provider using hand written SQL.
Also, a word of warning, apparently I can only create a database with that locale if "template0" is used as the baseline, and not "template1" as it comes from the factory.
Can support for this feature etc be added to the next pgAdmin version?