Version: (using KDE KDE 3.97.0) I've been having this idea for a session management strategy for the KDE desktop. Imagine that, in addition to the standard options - close, maximize, minimize - there were an iconify option, which would create a link on the desktop to the applications current session. The link would persist across logins, thus allowing the user to create shortcuts for his/her favorite sessions. I think the main benefits from this way of doing things would be a consistent, object oriented approach to session management, shareable by all applications.
*** Bug 255550 has been marked as a duplicate of this bug. ***
Ultimately this just needs to be done on a per-app basis. I am currently working on this. I've already done Dolphin and Okular is in progress with https://invent.kde.org/graphics/okular/-/merge_requests/247.