I can tell you that on my 2013, I was probably E45ish on an E30 tune during a zero degree day and the car shut itself down. I immediately blended down and the issue never happened again. You don't know unless you push the envelope, right? LOL.
That being said, IIRC we saw some fairly low pressure and it was able to maintain AFR. The 2015 seems to be more robust with the rail pressure so far but I don't know if this was due to the programming changes stated in the EPA certification application, the ACES fuel catalyst I've been playing with, or both. FYI My last set of logs were on a 48 degree day.
Even though the 2013 held AFR, I think it is important that rail pressure remains high. I read some research indicating too much E in DI injection has a propensity for wall wetting. Wall wetting causes preignition which we all know is undesirable. My assumption is that rail pressure decreases, atomization does as well which will only increase the chances of wall wetting to occur.
What I am curious about is whether we need as much enrichment at WOT with the E directly injected. All the research I've studied points to no. I also have a recent datalog where the car was kind of wonky (not bad, just different) but was at or near stoich a good part of the run without knock. If we can indeed back the enrichment down safely that should restore some rail pressure. If this strategy works at WOT then the same thinking could be applied to part throttle and cruising so there is a possibility of having a badass corn injected SHO that rivals or even bests the MPG of straight gas. Now wouldn't that be something?
