To master multiple songs, I would import all the final mixes into a new Pro Tools session(on their own tracks). Mute all but one track. Insert Ozone on each track and run the Master Assistant on your first track. Once you're happy, mute that and go on to the next until all are done(almost
). Then, set your SOLO to the X-OR setting so you can listen to all the songs while quickly switching between tracks(to make sure they sound consistent). Once you're really happy, use Track Commit to render everything.
OR: if your session is a higher sample rate/bit depth than 44.1K/16 bit and you want finals for CD burning, enable Dither on each Ozone and Bounce each in SOLO. BTW, if your sessions is already 44.1K/24 bit, you can simply export each clip to 16 bit and PT will automatically apply dither on the way.