Hey Felipe,
Although there would be a variety of uses for this feature, it is not currently available in the Casper Suite. My understanding is that this is one of those "when its possible, it will be included" scenarios. As I am sure you know, MDM is somewhat limited in functionality across the board no matter the management solution.
With that said, you may want to consider supervising your devices with the Apple Configurator. I don't know off hand, but that *may* block those devices from upgrading their iOS version. I am by no means sure of this, just a theory. It would take getting your hands on an older version of iOS, putting that on a device, supervising it, and trying to update to the latest version. Might be worth trying!
