I don't play Thralia as much as I want to for that very reason. When I have time to play and no one is on, do I get out the character who will be advancing levels or the one who has maxed out? Usually, I'm going to want to accomplish something. Then when others log in....well, I'm already on as someone else. But if there were some more incentive for lvl 40's to play, we might have a richer IG experience because they have a lot of story behind them by that time.
One thing that I was thinking about is cookies of a different flavor. Not for events obviously, but would it be practical for a random DM driveby
crafting xp cookie? or artificing? or mining? or whatever? I am currently trying desperately to stay motivated to have Thralia learn to craft here, but it's so hard. She was a master in Avlis, and here she can't make apple juice reliably. So I would give anything for some crafting xp.....just an idea.

If I take her back to Avlis to make things, it tends to be a while before I can get her back to Arkaz.....