I was thinking that for players like me, with many reincarnations, it is imposible upgrade many (and less all) the mazes.
So, my idea is this: the maze should be shared between progenitor and reincarnations. And if someone want to have more than one, there could be the option to build more mazes (at least one of each type).
This could let players to make bigger and better dungeons.
Another idea would be to have a private allod for the guild and a guild dungeon. If the maze we can create at our private allod is like an astral allod, a private guild dungeon could be more like a raid (or at least a more challenging thing, since all in the guild would work to make it better).