I use kagi translate a lot to translate between three languages. So I set the input language to “Detect” and that usually works fine. But there is one annoying thing (which also wastes resources) and that is that it often translates one language into itself. I think this occurs when the new input language is the same as the previously set output language.
So my suggestion for this would be to allow users to set a default output language for each input language which is then used when the output language would otherwise be the same as the input language.
For example, let’s say I translated something from Swedish to English. Next I enter an English sentence (which is correctly detected as English), but because the output language is still set to English, my English sentence is translated into English. Instead of this useless “translation” I would like Kagi to default to German as the output language for English. (Note that I am not suggesting that the output language should be overridden in cases where it does not equal to the input language. Only when both are the same, or when the output language, for some reason is unspecified).
Another way of solving this - at least for users like myself translating between a rather fixed set of three languages - would be a three-way translation mode in which the input is always translated into two languages i.e. the other two languages.
This mode would obviously use more resources, but since I often find myself translating back-and-forth between my three languages in order to better to understand nuances of meaning, it would be a very useful mode regardless of the issue you mentioned above.