Well it's not a good idea, because you don't control the same parameters.
Eg. on an inbound call, the wait time is something you strive to optimize.
On an outbound call, you have no control.... callees pick up when they please.
So if you run a report for both, the meaning of the wait time will be hard to understand.
I suggest that you create different queues for the tracking, and then if you really want you rcreate an aggregate queue that joins together inbound and outbound traffic.