yep that's what I was talking about. Yes the HP/LU. I was the one who mentioned the MDList Even though he mentions search he also mentions new manga so I'm thinking he means the Home Page / Latest Updates. I may be wrong he may be talking about the search page. I would rather they focus on filtering the Home Page / Latest Updates page. Some times I have opened 10 manga to find no updates in my language. It is one of the reason, while I like MD, I have switched back to another site I use to look for updated manga and come here more for the comments and discussions about some of the mangas.
Here is an example from my mdlist, https://mangadex.org/title/39471/hazure-skill-kage-ga-usui-o-motsu-guild-shokuin-ga-jitsuha-densetsu-no-ansatsusha moved up to the second position in my list despite there being no updates in my selected language and other in my list that have been updated recently. You can see the last English update is a month ago.
I'm curious what database they are using. I would think it would be easy to build language into the query so that it returns only updates based on language filters. Yeah you would have to tune the indexes include the languages. Date should be a numeric field and I assume they are treating the language field the same so indexes on them should be relatively quick