• The proxy settings are read via libproxy and can be used by QNAM that way, see T11530. That's also IMHO the only thing on this which is really still relevant.
• Cookie settings are IMHO application-specific, non-browser applications shouldn't be using cookies by default to begin with. Having this global and on by default predates privacy consideration (or rather the abuse of cookies in that context).
• FTP settings don't matter for QNAM, which leaves the remaining connection settings.

Done in https://invent.kde.org/frameworks/plasma-framework/-/merge_requests/595.

https://invent.kde.org/plasma/kwin/-/merge_requests/2925 removes the last use

In T15676#278274, @fusionfuture wrote:

Applications like a document reader or a web browser can be easily tested by measuring the opening speed of a document, but how can other applications measure their efficiency? For example in Plasma how to test one applet's efficiency? Can the current CI framework do it?

https://invent.kde.org/plasma/plasma-workspace/-/merge_requests/1770 addressed the remaining uses.

Ah, not in the 6 group, therefore I missed it. So the conclusion there is to drop the plugin stuff entirely? That would solve the problem as well of course. It nevertheless is a 6 blocker though, no?

https://invent.kde.org/plasma/plasma-workspace/-/merge_requests/1671 removes the last use

https://invent.kde.org/plasma/plasma-workspace/-/merge_requests/1667 takes care of the task manager part of this.

Second part: https://invent.kde.org/plasma/plasma-desktop/-/merge_requests/904

Solved by https://invent.kde.org/plasma/kscreenlocker/-/merge_requests/64

First part: https://invent.kde.org/plasma/plasma-desktop/-/merge_requests/896

done in https://invent.kde.org/plasma/plasma-workspace/-/merge_requests/1581

See also notes in https://invent.kde.org/plasma/kwayland-server/-/merge_requests/358.

https://invent.kde.org/frameworks/plasma-framework/-/merge_requests/452 addresses the first one.