Sync of multiple address books and calendars, possible?

[pedongroup]

Hi,

we are evaluating a zimbra deployment with BES(X) 5 for around 50 users, the 2 ways sync is working well (against a BESX) but I can't understand if the sync of only the PRINCIPAL Address Book and Calendar is a limit of ZCB, BESX or of the Blackberry system.

I've been told by the supplier we are testing zimbra with, that it's a limitation of the BES Express but I can't find any references about it.
Would it be possible to sync more than an Address Book/Calendar?
If it's a limit of ZCB could we sponsor the development of it in some way?

If it's a limit of the Blackberry system could we sponsor the ability to "merge" all the resources into the main one from the BB point of view?
thanks for your time
Andrea