X-Men #41 has a brief cameo of Adam-X fighting Eric the Red (of the Shi’ar Empire), frozen in time. This is due to Legion accidentally killing Professor Xavier in the past (rather than Magneto), and triggers the Age of Apocalypse world.
In the original Age of Apocalypse series, Adam does not actually have a role in it. Later, in 2015 during the Secret Wars event, Adam-X surfaces under the name of “Burner” as a part of “Magneto’s X-Men.”