Hello any possible readers!

Not sure if the right place would be this section (Plasma 5) or brainstorming. Mods, feel free to move!

I think the workspaces are an excellent idea in general. There are many critical posts about their window management, however. Here are the few problems which makes their usage quite laborsome currently IMHO:

Choosing on which application any window should be visible on, is way too difficult / time consuming. For example, let's say a user has 3 workspaces. That means he/she has 3+3+1 different choices (in any single workspace, two workspaces or all workspaces). This is all fine.

From the context menu of the title bar, one can choose the workspace(s) the window will appear on. The menu will close after choosing anything here. Now, it is easy to 1) add a workspace where the window will open in (i.e. change from "A " to "A+B") or 2) choose all workspaces. But these choices are not that common in desktop usage. For example, I claim the change from "A" to "B" is usually much more common, but will require at least 4 clicks currently! I.e. the process will be: change from "A" to "all" + change from "all" to "B" or, alternatively, change from "A" to "A+B" and change from "A+B" to "B". One possible solution would be not to close this submenu until the user clicks elsewhere, than the submenu. The choices are tickboxes, after all - so automatic closure is actually kind of against a UI paradigm of tickboxes - but, there is a conflicting paradigm of the context menu at play here, too. I'm not sure what would be a clean and sensible way to solve this, however current situation is certainly awkward. One solution would be a subwindow, and another would keyboard shortcuts (which seem to not exist at the moment).

This problem will be exacerbated in case the user uses more than three workspaces, and wishes to use combinations other than "X" (single activity) and "all".

These problems are especially problematic at log-in, as plasma will not remember where applications where open at last log out. The applications will be all over the workspaces, instead of at least roughly where the user left them.

Also, there should be a possibility to choose a user-defined special rule on which activity the window will be opened in, but this seems not possible currently, contrary to virtual desktops.

There are other minor problems, and altogether the activities feature seems quite a mess currently. One alternative would be to just drop the whole activities as a concept, but add some of the functionality to virtual desktops instead. Much of the features could exist this way as I can see them.

In summary / TL;DR: It should be way easier to change the workspaces where an application is visible from the UI. The UI should be designed so that most common switches are easy to do (from "A" to "B") and the fact that there are many combinations possible. Applications (windows) should at log-in open in the workspace they were opened the last time. The workspace an application opens in should be (optionally) user configurable, as it is for virtual desktops.

Maybe the whole activity idea should be just dropped, as the current feature implementation seems quite a mess. It might make more sense to add some of the functionality on top of virtual desktops instead.