Ok, fine. I’ll concede that point. Still, I see no in-game evidence that Magus can open/create time gates. It took enough effort on his part just to drag Lavos out of his pocket dimension, only to be knocked aside by the Giant Temporal Flyswatter of Doom (TM)
This might sound like a stupid question, but are we sure Magus is even supposed to survive the events of CT, cannon-wise? Lucca’s letter in CC seems to suggest she knows he’s still alive. Yet in the PSX re-release of CT, there is no sign of him in the expanded ending. Furthermore, Frog is shown in his human form (all thought you never see his face), which would only be attainable by Magus’ death.
Now that I think about it, you don’t see Robo in the new ending either…