I run a 52/34 (granted on Quarq/SRAM 5-bolt), and it works fine. I’ve found that this combo works really well for me.
Sure the front shifting is a little less crisp, and you have to make sure that you adjust the chair/derailleur so that you have enough chain, yet don’t have slack when in small ring/smaller cogs. This is really not a big issue since DI2 blocks out several of the small/small combos. I simply had to adjust the b-screw a bit.