Multilanguage search of KB in contextual search

Hi,

We have a requirement to search for KB articles in the caller's language in the 'search as' function of the contextual search on incidents so help desk members can attach articles in the caller's language. Therefore I would like to enable multi language searches in the contextual search of the knowledge base. Default behaviour is that KB search only returns results in the language of the logged in user. 
I do not want to change the systemwide property 'glide.knowman.enable_multi_language_search' to true because the behaviour of the user knowledge base should remain unchanged. Any options to enable multilanguage searching only for specific tables/the contextual search?

I tried adding a scripted filter to the contextual search table coniguration but this does not overwrite the user language preferences when searching.

Thanks!