If my primary monitor is to the right of my secondary monitor, do applications open on the primary monitor or the 'left' monitor? Also, do applications remember which monitor they were last opened on?
Not the parent, but I've also been using KDE in a multi-monitor setup for years (I have a 1440p primary monitor, and two vertical 1080p monitors to the sides). In my experience, applications open on the primary monitor, or on the monitor that is "active" (i.e. if you run Alt+F2 to bring up a run prompt on your secondary monitor and launch an application from there, the application opens on the secondary monitor where you launched it.).
Yes, applications remember which monitor and even location on the monitor they were last at.
