I want this so much as well too. Also the ability to just remove tags.
I love having the workshop so much. And I appreciate the work that many people do on it, so much of it is so out of my league my zoos would look pretty sad if just my own "creations". But when you have dozens of tags on an item, they show up on the various construction, habitat, nature and facilities tag. I understand the creators want to make their works as user friendly as possible and be as broad and adaptable throughout the various players games. I'm not asking they put in less tags. I'm asking for Frontier to give us a way to remove any we see fit. Different players will have different ways of tagging items.