This, so much this. I just came to mention exactly this.
I just had my system winterized today. When they use the "normal" controllers (Pro-C is my old controller), they can blow-out 2 or 3 zones at the same time, since they have enough air pressure and with the simple pins they can easily activate multiple zones at the same time. Since with the rachio I couldn't do this, a process that normally would take 15 or 20 minutes took almost 45 minutes.
They even implied that it might make the cost be higher, since it's limiting the number of houses they can hit in a day.
It would be ideal if there was a way to do a similar thing in the app.
Maybe a special blow-out/winterization cycle that would allow me to pick multiple zones to turn on at the same time?