composite ticketing and packages in a museum setting

Hi all,

We're a large GA venue that offers Tours, Audio Guides and other extras, and we want to explore the use of composite ticketing.  I know this would mean the use of flex packages, but our GA tickets are currently in one season, our Tours are in another, and other Add-Ons in a 3rd.  While I'm no stranger to subscription setup, in the past, I've only had to build packages where everything resided in the same season.  Am I correct in thinking that all perf groups must be in the same season?  If so, are there any fun tricks that I'm missing that could get around this?  

Thanks!
Kathleen