"Tabs" for quickly switching recently used languages

Inspired by an UI attempt, visible below, where the dropdown was smaller and did not take all the space, making it look like a "Tab". The empty space looks like it could be populated by other, unfocused "Tabs"

Add a "Fav" button on each side, and allow user to practically "bookmark" a language.

They get a second, smaller button aside from source selection. They click on it to switch to bookmarked language
Like, on the left, i translate frequently from german, english, or french: I should have these three as "tabs" so i can quick switch the source language.

Remove them by "fav"-ing them again. The icon should change

Target should have the same. Just click on a fav to bookmark a target