You can minimize trips through DA/AD by running your multitrack mix through the 2-bus straight into your analog processors and printing to a stereo track in PT, summing and mastering all in one step. Import the first mastered song of a project into the session of the second song for comparison when matching levels/EQ. Rinse and repeat. If you document all of your outboard settings then you can have recall, giving you the ability to revise the mixing and/or the mastering at will. You will also have more control over how the mastering interacts with the mix - if the snare, for example, is getting squashed by the mastering, you can address it in the mix. Once all songs are ready, arrange them in a separate session and do final listening check. It's how I do it...
You'll be wearing 2 hats at once, but the ability to recall and revise everything is an effective safety net.