Plasma’s restore session functionality has started working for me relatively recently, but there’s one thing that bugs me: all my windows are just dumped together into the same activity and workspace I’m in at login, so it becomes a big mess.
Is there a setting somewhere that tells it to respect the last position of the windows?
Your are right, it’s not implemented yet in Plasma Wayland. It must be done in Plasma/KWin itself since top-level Wayland windows can’t position themselves on screen and don’t even know their coordinates (and doing it on the application side is not really correct since not all apps will support it and it duplication of work and code, while compositor can do it consistently for all windows). However it just doesn’t work yet.