Hi Hans,
as I understand your use case, I do not think metadata localization is good option here. As Joseph mentioned, it is tied to the language user has set in their profile (that also affects the actual language of the UI).
You might consider the
Renaming Utility to rename objects in some of your workspaces. You just provide object identifiers and workspace/client identifiers for those that should have different names (and those names) and let it run.
If you have some custom field placeholders in your model, this is also ideal for them, since it can not only rename them, but also hide thise that are not used.
Note that if you are using the Lifecycle management, a fresh release/rollout will chanhe the names back but you can always run the rename again afterwards.
Actually depending on how long it runs, you might consider running it regularly after workspace provisioning (to potentially apply renaming in the newly created workspaces).