Hm. I mean, at some point, you'll probably find that your group has to hold DPS before the 52% threshold in T13, and that the adds phase can be dealt with pretty comfortably. So, the only real advantage of min-maxing in T13 (besides... well... min-maxing for it's own sake) will be that it shortens the duration of the final phase, potentially reducing the number of mechanics that you have to deal with.

I mean, progression should be your priority, and the DPS check in T13 is pretty real. But between all of the mechanics that screw you out of uptime and the incredibly stupid way that they programmed the adds spawns in phase 2, T13 kind of sucks all the fun out of maximizing DPS. Just my two cents.