It is very simple, if some event need pnly certain chars and stars, show it in advance so we can plan in advance.
I know it is not problem for high lvl guys with many chars, but for low lvl it is problem.
I just missed one event only because i focused on char i wanted to try ( was not needed), instead of char i just liked to try, but was needed fpr that event.
And similiar for another event, i did have chars, but they lacked stars for him. Again, not nice.