Edit in addition to last post: Am 17.01.22 um 16:40 schrieb mito:
OK, now it seems to work as you say – in KDE5/Plasma. My problem was in Trinity, which is KDE3.5; screens are managed a bit different there. So one just optionally needs an additional 'liftX screenWorkspace' hook?
On the other side, clients in Trinity don't swap monitors automatically if there was an empty screen; which was handy. They just were sticky if you don't shift them manually.
Now in Plasma clients swap monitors again though I changed from "W.greedyView" to "W.view"...
In other words: How to make clients sticky to a monitor/screen (in KDE5/Plasma) when changing workspaces even if the other screen is empty (to not swap them back by an extra mod-{e,w,r})? It's quite frustrating when properly arranged clients are always swapped to the wrong screen after it happened that was empty before on another workspace.