I often use tags in conjunction to hierarchies (easier to run queries across my entire library).
here are many cases where I want to apply the same tags to all the children of a particular card (they can still have additional individual tags on top of this).
I do this by creating a filter and then all new cards are automatically given that tag when I create them. This often leads to having lots of tags throughout a card hierarchy (#Uninotes #MedicalImaging #MRI for all my lecture notes related to MRI)
It would be great quality of life improvement to be able to have a button “apply all tags as filters” that I could click on the parent