I tried it out today, the glitch still works in singleplayer, but the doors lock as soon as you enter the room. You can still explore the "blocked off" areas though, you can go up to where Trace is standing and shoot at him, but hes invulnerable, or you can push him off the edge and he'll continue fighting Noxus from the floor. I was also able to scan five of the locks in that room, but the last one (near the magmaul door) couldn't be scanned because a force field blocks access to that cranny until you kill Noxus (there are two force fields, the one that goes away after Noxus in front, and the one that goes away after you kill Trace in the back)
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