Sure, turning logging up or down does require me to edit a file, but that's fine.

You're missing out, then :-)

My Log::Any::Adapter::Daemontools has an option to adjust the log level in response to SIGUSR1 and SIGUSR2

My yet-unreleased-to-cpan Plack::Middleware::DynamicDebug adjusts the Log::Any log level per-request depending on a magic cookie, so if something is going wrong in production I can visit the (password-protected) page that issues the cookie, configure a different log level, and then get full trace debugging written to the production service logs for only requests from my browser. It also adjusts the logging of Catalyst, DBIC, and turns on Carp::Always, but the sort of deep integration with the app is why I've never gotten around to making it a general CPAN module.

Is there really no way to adjust Log4perl's log-levels on the fly?