Labels are incredibly useful, however, they’re tedious to add/remove.
I propose adding a “Mass edit” option to the following:
Settings > Areas, labels & zones > Labels > Overflow menu
The subsequent page resembles Settings > Devices & services > Entities. It additionally has a drop-down list to select a label (including, create a new label). Each entity lists existing labels and has a check box to add or remove the label selected in the drop-down.