If MB.org websites are launched with the tport parameter passing a numeric value it enables the tagger button. But there is no way to disable the tagger button again.

I propose allowing an empty tport parameter (e.g. https://musicbrainz.org?tport=) or if that causes issues passing "tport=0" to explicitly disable the tagger button again. This should unset the tport parameter in the user session and hence disable the tagger button again.