Ohhhhhhh. I entirely misunderstood the UI. It had a toggle for quite a few releases already. This is embarrassing.
#[0]
I apologize I misunderstood what you wrote earlier. I was frustrated because I thought you were dismissing my requests but in reality the UI was just confusing. I would have recognized the toggle a long time ago if it had a symbol like 🔄between the two language names instead of the word "to". I'm sorry I misunderstood this for a long time.
In that case I'm missing only the ability to turn translation on for languages that are disabled. There's two reasons it might be disabled. One is because it is one of your system languages (or installed input method). The other is because you previously selected Never so the UI had disappeared.
Could you please consider adding "Translate" to the note context menu in this case? Or you may have a better idea.