So, we have this page here:
https://community.kde.org/Krita/Brushes_Preset_Preview

And I was thinking, the majority of those sample icons are SVGs anyway, so maybe make a vector icon library out of them?

Here's a sample file that you can put into share/krita/symbols or open with Inkscape and use the symbol docker. It only has one of the files, and the blur filter currently doesn't load in Krita. The idea is to extend this file and add extra vector icons to it, so people can assemble their own icons quickly.

the only weird thing is that Krita interprets the vector layers default unit to be point and not pixels. So a vector layer in a document of 100x100 pixels will consider itself a vector layer of 100x100 pts, which means that if I import a 100x100 pixel document etc. etc. etc.