Great timing. Today I discovered that the iMac 24" screen can't be rotated. I have it on a VESA mount, so I can rotate it physically, but screen rotation settings are inaccessible (even with the Option key) via system settings. When I attempt rotation via displayplacer (tool in OP), it just complains that it "could not find res". There's a surprising lack of good search results on this. Seems to be related to the iMac overheating, but that's information coming from a random forum post that I found, not from Apple.<p>Edit: found Display Rotation Menu via DisplayPlacer Github issues, which is so far the only tool that worked for me.