HowTo: Change / Move data directory after installation

Question regarding solution 1, step 6 (I’m currently planning the data dir change): basically we update the storages table by modifying the id column value. So all files in the filecache table will just continue to work.

When I moved my data directory once in the past (~ 2018), I did not do that. This is why I - now and until today - still see this in my nc_storages table:

numeric_id | id                               | available | last_checked
--------------------------------------------------------------------------
20         | local::/var/www/owncloud/data/   | 1         | NULL
39         | local::/usr/data/nextcloud/data/ | 1         | NULL

20: Old data directory until 2018
39: New data directory from 2018 until 2026 (I’m moving the data dir once again now because of PHP-FPM security hardening: /usr/ is read-only now — data dir does not belong there)

When doing

SELECT storage, COUNT(*)
FROM nc_filecache
GROUP BY storage
ORDER BY COUNT(*) DESC;

I’m getting quite huge numbers for the old storage with id 20 (not that much as for 39 and for other storage IDs starting with home:username, but anyway a few thousands).

Thinking of handling (storing and backing up and archiving …) those - likely completely outdated und unnecessary - entries in nc_filecache already for years, wasting backup storage etc., here`s the question:

Is there a safe way to remove those entries from the database?
Is that maybe what occ files:cleanup is intended for?