so has anyone come up with a viable solution to tag several brushes at one time, or are we currently stuck clicking on each brush and typing in the tag over, and over again?

Yeah; I can see this one to be a bore; did one or two and decided I probably don't need this feature anyway. lol

lo' and behold, Reddit came to my rescue today, when one of the redditors said this:

"...Create subfolders in your brushes folder (.gimp2.8/brushes), and if you type the folder's name in the search field, only those items will appear which you put in that folder.
There are pre-defined stuff in the main gimp brushes folder. Just click on the down-arrow in the search bar, and it will show you the available tags. If you create folders by the same name, it will applies the same tag to the resources in that folder.
Discovered this some minutes ago "

In other words, to create a tag in gimp, you can also add a subfolder to your gimp-2.8/brushes folder, and any brushes in that folder will be tagged with the name of the folder.

How cool is that?