When we build the query for another wiki after textcat detects a language, we are still using the local wiki's template boosts. Somehow we should source the template list from the other wiki.
This is currently only working on enwiki (boosting) but when searching on ruwiki, it doesn't use the boosting for enwiki in the results.
This shouldn't slow down the release of TextCat into production, but we should do it within this quarter. And...it might be a super easy task or a super hard one, we'll have to investigate first to know for sure.
Current implementation also seems to use caching with $cache->makeKey( 'cirrussearch-boost-templates') which seems to be wrong as cache can be shared between wikis, IIRC. At least, I don't see anywhere that it is keyed by language.