I've tried changing the default ("") log level for "INFO" to "ALL", via jenkins/log/levels, but this doesn't do anything. As it's available and described as a thing, there should be a note explaining this constraint. It doesn't have to be the full details, it can be a link to a page that explains them.
# If you create a new logger, its jenkins/log/loggerName/configure page has a field for a logger name, and when you type, it offers completion suggestions. The main page jenkins/log/levels doesn't offer suggestions. I don't think there's a good reason for this discrepancy.
There is a lot of other strange behavior about the main logger. I really don't understand why I can't seem to use it to (sorry, lost train of thought, filing anyway, we can fix later)
Improvement
Minor
