I had wondered, particularly after the use of Mon-El in the Superman role for a brief time by DC (when Superman was off-world? Part of some Krypton related arc?), if Mon-El might not have a series of brief times out of the zone over the last 1000 years, or adventures *in* the zone (threats to the zone itself? An invasion of the zone by some other dimensional creatures or force?).
There's a thousand years of history there. And the zoners appear to be able to watch stuff happening in the 'real world' at times, although its not clear if they can do that from anywhere in the zone, or only in specific locations, or at specific times, which means Mon-El could, in theory, know all sorts of 'lost history' about stuff, from his viewing of those historical events of the last 1000 years. Even stuck in the zone, he might have had some impact on some things, if some special people, psychics or magicians, could make contact with him (or he with them), and he became aware of some horrible thing about to happen, and went and found the various psychics, sensitives or magical folk who had shown an ability to perceive him and dropped them hints (through whatever sort of communication he might be able to have with them) about the impending danger. (Which could even be retconned into some old stories where the Phantom Stranger pops in to warn the League of a threat. The Phantom Stranger was one of those few that could sense a zoner jumping up and down in front of him trying to get his attention, and it was Mon-El who warned HIM about the danger! But that would have been too long to explain to the League "Yeah, some ghost from another dimension warned me. He looked oddly like Superman?")