simon1222 I can think of two non-stable ways to achieve this, with the risk that it breaks in a future Flarum version.
First you could remove the existing filter with a service provider. Extend 'flarum.filter.filter_mutators' in the container and remove the mutator you don't want, then add your own. This is actually something we could add to the extender. Just make sure sticky is a dependency of your extension so Flarum will run sticky extenders before yours.
Another option also using a service provider would be to bind your own class as an alias of the original: $container->bind(PinStickiedDiscussionsToTop::class, YourOwnMutator::class) (with correct use paths). Then Flarum will use that class instead of the original.
