@UncTom
There is an option to restrict your feeds to the list of languages you want to see.
Check out "Filter languages" here:
lor.sh/settings/preferences/ot

But it's also not ideal at times because sometimes the posts are marked as wrong language and missed by the filter.

And yes, the option you proposed would be better, but I think it'd cost much more because Mastodon uses DeepL API and translating one post and translating a whole feed is a lot of difference in the size of work.