Hello @FlatErik
I'm afraid you can not "unselect" the relationship category inside the templates, since they will always take the complete object "as-is" and replicate it or use it as mass-change basis.
Usually (with any other category) I would say you can simply "clear" all entries from the category you don't want, but that won't work for the relationship category unless you remove all entries that created any implicit relations 😕
I have not red every post here - could you sum up what's the problem?
Best regards
Leo