This is a very needed Idea, I know it is a pain for a lot of companies that want to make full use of association labels.
@dsecareanu, yes that would still require Excel manipulation for each contact that you would like to add the association to. Then things get more complicated with multiple associations, multiple labels for those associations, and parent/child hierarchies. So even doing it by hand is kind of difficult, but probably better than trying to do it through the UI.
I think a lot of companies are simplifying the way that they use labels to deal with this and not using them to their ful potential. But they can be super useful.
Full disclosure, I work for Insycle, which can help with advanced association management, including updating associations+labels in bulk. Additionally can help manage multiple associations and parent/child hierarchies.