What do you think about having it disabled instead of hidden?

(I'm expecting bug reports "no information about the data location" if it just gets hidden - if it is just disabled, at least people will know where it is)

Replace this with http://doc.qt.io/qt-5/qstandardpaths.html (I think you need QStandardPaths::AppLocalDataLocation)

I didn't consider it an issue as its just data that they would never ever interact with. People never cared where their post-it notes etc are stored.

Making it disabled will more likely be the cause of people not being able to figure out why its disabled. And they start to look for a way to enable it. Causing more confusion.

How does replacing it with a text label sound?

No, the Qt one includes the appname. So I'd get;

~/.local/share/kded5/

Are the Windows/Mac platforms relevant at all? If not, I'd just like to keep it the way it is.

Fair enough. Leave it hidden, and if we get complaints, we can change it later.

Can you try QStandardPaths::GenericDataLocation and append "/plasma-vault"? (if we are changing the path, let's use the full name of product just in case other DE people decide to call something of theirs 'vault')

QStandardPaths::GenericDataLocation
Returns a directory location where persistent data shared across applications can be
stored. This is a generic value. The returned path is never empty.

Windows and Mac are not relevant at the moment, but I'd still like it more if we relied on Qt implementation instead of simulating what QSP does.