Hi again
Back with a further progress report!
I'm still having trouble getting celebrators to consistently offer sugar skulls. It seems to be tied mostly to sims with existing relationships.
I have a household of 3 sims who are trying to complete the collection, and they've all been using the tombstone daily to offer skulls.
If the celebrator is somebody they meet for the first time, it generally only takes about 3-5 interactions before they'll offer a sugar skull. However, if there's an existing relationship it frequently takes much longer.
In the most recent cases, it took 12 interactions, 17 interactions, and the worst was 24 interactions and a maxed friendship bar (they started at good friends), before the sim stopped freaking out every time I requested a sugar skull.
