Au Ra and purchasing expansion on 2 systems

[Sasha]

And that is the thing. If you can play as them without the expansion (after having it installed in the other system), how far can you go? Gain new skills, new levels? At which point would they put up a wall and say 'This is as far as you can go, you have to install the expansion'?

Would be much easier (but not user-friendly) on SE's part to just blanket it over: Any expansion material, content-wise, that has been detected on your character will require expansion installation.

The simple thing to do is to let you play as an Au Ra as its already in the base game, however not letting you create a character because you don't have the expansion.