
Switching between landscape and portrait is done with both AutoHotKey and 12noon Display Changer, since switching via windows takes way too long.
The two hotkeys that I created are Win+PgUp and Win+PgDn.
#PGUP::
run, "C:\Program Files (x86)\12noon Display Changer\dc64cmd.exe" -monitor="\\.\DISPLAY2" -rotate=up
Return
#PGDN::
run, "C:\Program Files (x86)\12noon Display Changer\dc64cmd.exe" -monitor="\\.\DISPLAY2" -rotate=right
Return
The only downside is that the viewing angle in portrait is a little more critical than in landscape.
Also during unpacking, the monitor base, which can move the monitor up and down, was locked in the lowest position with a locking pin. Nowhere does the manual tell you to slightly press the monitor base down to remove the locking pin.