It is apparent they designed the bike with racetrack performance in mind, as it is obviously way overkill for anything anyone would do on the street. And as I am sure you are aware, on the track you are downshifting as you are braking, and you definitely do NOT want the throttle open in that scenario. That is a quick way to lose the front (almost happened to me racing the R1 at Road Atlanta 5-6 years ago).
With the design/intended purpose of the bike, and with the way the electronics are intended to maximize performance, I see absolutely no reason for them to allow downshifts with the throttle open.
On the street, that stuff really doesn't matter. There are no trophies awarded, nobody is tracking the time it takes to get to the store and back. Just ride it. If you need to downshift, close the throttle and do it. Or if you want to keep the throttle cracked for some reason, pull in the clutch.