Ok, here is my take on the whole thing. CZ will never say it is ok to use +p or +p+ ammo for liability reasons...PERIOD!
All CZ's are made for NATO spec ammo. This is a much higher rating than SAAMI in the states. For a 9mm +P+ is typically rated around 39-40,000 psi , NATO is rated up to 42,000 psi.
Just for this reason, I believe you can shoot any d*mn thing you want for as long as you want. The guns were built for it.
You cant blaim them for their actions and lack of comments...its company policy through out the world to keep a "safety buffer" in any area that could be a problem, regardless of how slight the risk is.
Shoot well