Now that I've accumulated dozes of brush packs in addition to those installed with Painter, I wish there were a more efficient way to organize groups of Brush Categories into separate libraries or visibility sets.
It would be great if we could select multiple Brush Categories at once, then:
you actually can hide brush categories selectively! or, at least, you used to be able to do that... I'm not sure if current painter release manual still has an instruction how to do that though.
regarding everything else it's indeed not currently possible and painter's growing library DB could use more efficient tools.
the problem is no one can really tell if your feedback will ever be taken for consideration by the corel team.
Yes, it's still possible to hide brush categories selectively -- it's just a little tedious to do it one at a time. ;-)