We use timeline_fu for a simple timeline in iEye. The problem is that objects can be deleted, making the timeline events freak out a bit, since their subjects might not be there any longer.
One option is to make sure all timeline events referring to a deleted object is deleted as well, but that makes things disappear from the timeline.
Since we don’t want things to suddenly disappear, I installed is_paranoid, so the objects still exist, they’re just hidden by default.
Now, this didn’t help much, since I couldn’t find a easy way to decide which finder timeline_fu uses to get the objects. Which means it’s time to start hacking things.