I don't see why they would book you on an alternative airline if they can deliver you to your destination just in a different class of travel.
The re-routing option is dependent on how much you push and if they cave. I had explored an MUC re-route to the 388 but again found it too much of a hassle to be honest. Not sure why you want to travel from PRG to ZRH/FRA,. If you are inflexible to switch to a day prior or after, how can you be so flexible as to switch countries especially ZRH being quite a trek.
I purchased a FIRST class ticket, nothing FC about EK's responses to date
FRA & ZRH are not far from PRG, & i'm a frequent flyer
i can spare a couple of hours from my schedule to travel in the class i paid EK for, but not 24 hrs.