For now, Update 10 is still an Alpha release and shouldn’t be deployed in a full production environment.
However, if Update 10 had been available for deployment in production, making it possible to select the Caller ID directly in the applications, and users needed to select the Caller ID from the application rather than through an outbound rule prefix that forces a specific Caller ID, I would duplicate the DID in the SIP trunk, add a prefix to it, and assign it individually to the users who need it.
For example, if the DID is 5147770000 and the extension of the user who needs the Caller ID selection feature is 2345, I would add the same DID again with the extension as a prefix:
2345.5147770000
I would then add two Outbound Caller ID Reformat configurations.
The first one would have priority and would handle the Caller ID without any customization:
Source Pattern: (5147770000)
Replace Pattern: \1
The second one would be used to clean up the prefix:
Source Pattern: (....).(.*)
Replace Pattern: \2
I’d simply explain to the users that they should ignore the prefix, meaning the extension followed by a dot, followed by the Caller ID.
Obviously, this takes longer to configure than simply enabling an option in a Queue, but in a situation where that option isn’t available, I believe there are several workarounds available to achieve an equivalent result.