[Using Sakai] Combining Course Rosters in Sakai 2.7

[Reeves, Hannah H.]

Dear Sakai User Community,

Tufts is preparing to launch Sakai 2.7 in production on August 1st and is running into an issue with combining multiple SIS feeds into a single site. Here's the use case:
Our sites are auto-provisioned and a separate site created for each separate feed in SIS.
Several language faculty wish to combine multiple sections of introductory language into a single site, as they've been doing in Blackboard.

We've been experimenting with combining several course rosters into a single site using the Admin Sites tool and pasting the externalSiteID value for each course into the base course's field, delimited by commas; we've also tried using semi-colons. This did not successfully merge the rosters with the SIS feed update.

We know it's possible for the end user to do this as a one time merge (kudos to Pepperdine for their excellent documentation on this), but we would prefer to have admins do it for them, so that faculty don't need to repeat the process throughout our add/drop period to pick up the correct list of enrolled students.

Can anyone tell us if this is the correct way to go about merging sites that are auto-fed from SIS? Is there another solution that we've missed or is this just not possible in 2.7?

Thanks,

Hannah