Adding Personnel to Events - suggestion based on the recent change

The new tool for adding personnel to an event automatically adds the individual to all sessions. 

We frequently have events where 50% is being taught by one instructor, with another picking-up the other half. In extreme cases, we may have even more instructors allocated to an event.

Currently, we have to either

a) add the instructors to all sessions, then edit the sessions in the outline tab to remove them from the ones they don't need

b) navigate straight to the outline tab and add the instructors to each session individually, before navigating back to the setup tab to make one as the Primary Instructor

I have a suggestion:

It would be great if we could add personnel, then untick the sessions that are not relevant to them by clicking the relevant numbers:

This would mean fewer clicks and waiting than navigating to the outline tab and editing each session.