I created a feature with a field definition with choices. These choices are bound to language dependent resources using the $Resources:file:key system. Resource files are included.
As the feature is activated the field is added to the site fields. All document libraries that use the content type have all the new field with the choices.
The subwebs (in different languages) have the field too - with the same options in their language.
So far so good - now the problem: I need to add new choices to the field. And that's where I got stuck. I tried several things like deactivating and activating the feature. I tried to remove the FieldLinks from the content-type and adding them back. I even tried to remove the field from the site completly. Nothing worked.
Of course I could read out the site field choices and add them to all document library fields. But this would overwrite choices language in the subwebs with the root-web language choices.
Is there a (good) way to update field options (add one or two) without losing the translations and without introducing a new location to maintain the choices in?
Update
I tried DisplaceOnUpgrade="true" in the Field definition. That updated the site field, but not the existing document library field.