This does indeed work, thanks!

I just installed blackbox, and as expected, the window starts as a fullscreen window with 2560x1600 including its border which shows up right away.

Well, if I start the app on another desktop than "0,0", E will still crash but will then successfully restart, at which point the window is still the same size and does have a border, so I guess it's safe to say that it should have one in the other scenario.

Attached is the xprop, during E crashed state.

Something else I noticed while reproducing the bug: it does not happen when I start the application before I start anything else von the first vdesktop.
When I start FreeCAD as the first application, it will still have the full dimension of my screen (2560x1600), but now it will be positioned below the top bryce and off-screen for a large portion, but not crash.

I'm not entirely sure if I can.
When I run E in valgrind, it will still crash, but it will never show the error handler dialog, so I can't gracefully exit it.
This means to get a meaningful log I have to manually kill it, and I'm not sure if this invalidates the log to some degree.

Crashdump of the issue.

Just for completeness' sake: The issue is fixed for me as well.
Thanks!

I use most shelves on all desktops, but I always have one desktop with no shelves and usually one without the pager shelf.

I do use different settings for different shells, most shelves are either above everything or below windows.