What about envelopes???
You could sort of automix by tweaking volume and panning envelopes on each of the tracks.
I do this alot with Acid where I tweak the envelopes in real time to hammer out a direction for the mix.
then when I have things close I do final tweaks in a "step record" kind of way where I tighten up a tweak, listen to that section, stop, adjust, tweak, listen, stop, adjust.....etc.
Of course if you plan on messing around with FX envelopes than you better have plenty o juice cus that sucks power.
I havnt really gotten the chance to try this technique in CEP but a little spline play should get you closer than mixdown trial and error.
-mike