Leveling for AC is not critical. It could probably run OK upside down, but condensation drains into a pan, you want openings low enough that the pan doesn't overflow. Leveling for refrigerator os more critical and usually good enough for AC.
I actually level for my stovetop, so bacon grease and eggs don't run to one side, or over, the griddle. My rig, this puts the refrigerator well within safe range and AC draining onto the roof. If staying for a long time, in hot humid weather, I might mislevel slightly to control where the condensation runs off the roof, preferring to send it to streetside gutters rather than drpping on my head as I go out the door.