DEV KIT Question: Localization lost through Export & Import from Data Table

Hello, I have a small question:
As the mod 75% woman changes all the names to english, I like to make a version with some other features also, that does not change the language.

When I simple use the original SpawnData Table and make a “Mod”, all is well localized.
When I change something in my mods SpawnDataTable-copy, the resulting mod still is fine localized.
But as soon as I export the datatable to csv or json, and then reimport , it is not localized any longer, even the imported datatable looks like the original, still containing the “NSLOC” entries.
Is this a bug or has to be done something ?
I had to learn this the hard way, as I at first exported, made a half day of changes only to find out that it resulted in a mod with english names. Then through analysing the single steps I found out what I described above.

I think, only exporting a datatable & then reimport it should not cause the loose of the localization.

To handle the more then 5000 entries in this datatable makes it not desirable, to work without an external tool here. But before using this, it has to be sure I can reimport the datatable again - localized.