Vlad I would love a dedicated Kagi translation site.
The lower tier models like GPT 3.5 and Claude Instant V1 still provide more natural sounding translations to me.
Using LLMs instead of machine translation APIs would also allow you to implement more influential "tones" than DeepL.
For example, let's say I select English -> Japanese. Japanese has a lot of conventions for formalities, so if I wanted the tone to be like I'm talking to a friend, I could select or type in what tone I wanted the translation to be in, and Kagi Translate would pass this in with the LLM as context.