screenshots visualizing the issue
Handling page titles that natively are supposed to inherit the opposing language direction within a global language direction context will result in display and (auto-complete) lookup errors when the title includes certain characters (e.g. with parentheses which do not have an inherent direction).
A solution might be to store the language direction as per site and have direction applied locally to every site/page link. However, sites may contain page titles of ltr and rtl direction.
In the Wikibase repo extension we have a list of all site links. This list contains links to several sites. In a Wikipedia context this is the list of language links to articles in different Wikipedia instances, so it is a list full of mixed language directions which currently is displayed either in a ltr or rtl user interface depending on the user language.
This problem is basically the same as in MediaWiki core when displaying rtl and ltr text in parallel, see for example #28411.