Working with different localisation project files is a problem on it's own, so I will not talk about it here.
What would be of great help would be an additional Property Manager option if one wants to delete an existing Property.
If the Property, which needs to be removed (e.g. a duplicated Property in two different languages in my case), matches another Property Type and Value with a different name, there could be a Delete and Replace (or merge) option available.
Open