Mockup looks incredible. Add pinned apps for quick launching my favorites and this would be a perfect workflow.

I'd like to propose that there be added a default shortcut to restart plasmashell and/or kwin - essentially a "uh oh, things are weird/broken" command.

Could window snapping in the corners (upper left, bottom left, upper right, bottom right) be bound to some modifier plus Home, End, PageUp and PageDown?

+1 for the idea of Discourse

+1 for IOTM as default (but not a fan of left-side panel)

In T11743#222629, @zamundaaa wrote:

+1 for this idea :)

It personally think that a new "layout" kcm would still make sense. Themes and layouts are for most people completely separate things. A UI that combines theming and layout would IMO mostly be confusing - a global theme having a layout you can optionally apply is fine I guess but having a global theme that is only a layout just seems wrong.
Additionally, an easy way to save the current layout for later would also warrant it being its own kcm a bit more.
Saving the layout would useful be for making a backup just in case Plasma manages to lose the settings for a monitor, testing a new setup with an easy way back or for easily replicating of the same layout on a different machine (say, copy the layout from the desktop to a new laptop).