> it's straightforward to change the default.

Care to share? Looking at https://systemd.io/TEMPORARY_DIRECTORIES/ and I don't see any description of how to change the default behaviour dictated by systemd.

How do I disable the automatic file reaping? How do I configure the maximum age of temp files? Neither are mentioned. The bulk of the page is just a long list of passive-aggressive suggestions about how users are doing things wrong.