OS customisation ramble
Because of my high DPI screen, all icon customisation iPacks I've had experience with fail to give proper symbolic icons to my explorer sidebar - because the symbolic icons are 16px, while my screen renders the 32px versions.
I tried setting each folder manually, but for some reason some folders wouldn't change, while others would. I have no idea why it was behaving like this, given they're all system folders.
In the end I just did extra patching by hand, but now my sidebar actually looks nice. Gave custom folder icons to some of my own folders too.