Steps to reproduce the issue

Disable logging options in general site settings and disable plugin System - User Log. Then delete all log files from the administrator/logs directory.

Now let's play a little with the logging parameters.

1. System -> General settings -> "Logging" tab, turn on the Log Almost Everything parameter.
   Install a nightly build, monitor the administrator/logs directory.

Created everything.php and joomla_update.php files, which are mostly identical when updating Joomla.

2. Without deleting anything, try to log in to the site, having previously made a mistake (for example, in the login).

Created file error.php that reports an authorization error. In addition, the error is duplicated twice in file everything.php under the heading INFO and WARNING.

3. Enable plugin System - User Log and its only parameter, then repeat the authorization error by entering an invalid login.

We will get a situation identical to point 2.

4. System -> General settings -> "Logging" tab, turn on the Log Deprecated API parameter.

Created file deprecated.php, which is growing before our eyes.

5. System -> General settings -> "Logging" tab, enter database, databasequery, database-error, deprecated, jerror in parameter line Log Categories, Log Category Mode -> Include.

Created file custom-logging.php, which mostly contains category deprecated entries.

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Given a fast enough test, I suggest:

1. If initially the task is to separate all types / categories of logs by files, then I would prefer to have the parameter not Log Almost Everything, but Enable logging and through showon="logging:1" in XML to regulate the creation of files by category. For example: Log Joomla update, Log outdated API, Log authorization errors, etc.

2. Obviously, the System - User Log plugin does not work (see points 2 and 3). It must be deleted, the parameter moved to the general settings and the logic "repaired". The plugin was needed BEFORE Joomla 4, until the logging options appeared in the general settings.

3. The Log Deprecated API parameter requires a description that the parameter generates overhead and should be used with care. I can't judge objectively, but it feels like the site is getting "heavier" and the file size is growing very quickly (literally in a couple of minutes it reached the size of 10 Mb).

4. Given that there is a corresponding parameter for the outdated API, this category should be removed from the description of the Log Categories parameter (the logs are duplicated in the custom-logging.php and deprecated.php files). On the contrary - this parameter should be used to catch quite rare or "unpopular" (so to speak) categories and which will not be included in the list of all logging parameters. Alternatively, it can be implemented as a select, listing all available ones (alas, I don’t know how many there are in total).

5. In the general settings of the site, there is not enough option that would delete files after some time or size.

In general, I decided to combine all the information in one issue, since there are several suggestions for improvement / correction and implementation may differ. Information for thought.