Did you see the docs here: https://docs.mendix.com/refguide/translation-generator/ ?
So yes importing modules will generate errors because the translations are missing. But with this feature you can translate quickly all missing stuff. And yes, Mendix is working on how to better support module translations. But that will still take a while.
Regards,
Ronald
Hi
Open the Project
> Settings
> Languages
modules contain hardcoded captions (e.g., labels and buttons) that are not translated using the translation system.
Go through this documentation
By default marketplace modules will use English US, this will avoid the issue for the future. For now if you add in translations for those captions for English UK it will resolve the errors. Alternatively you could switch to English US default.