Currently, when selecting a language that has a converter, Special:Translate requires the user to select something else. It is just a plain-text error message. Here's an example from Kazakh:
It could be more user-friendly. Some immediate ideas:
- Don't allow selecting languages that can't be targets in ULS.
- Change the plain-text message to direct links to translating in the variants.
- Redirect the user to the default variant.
There could be some more improvements.