Exposed filter facets don't run pre_query stage processors

When migrating a site from facet blocks to Views' exposed filters, I noticed that the search result page slowed down massively.

We have about 100 facets on that search page. A custom processor acting very early at the pre_query stage exists that reduces the facets to the relevant ones for that search. But this processor has not been used anymore. Doing it's work at a later stage makes no sense as the majority of the havy load would already have happened then.

So I suggest to enable the pre_query stage for exposed filter facets. But it needs to be configurable which processors are running. For example it makes no sense to run the URL processor which is part of the facets module and acts on that stage.