It would have been better IMHO if they had slide-in-frame like CZs are known for.
Metal slides don't ride on polymer frames internally OR externally, else the metal would chew up the polymer. That's how Glocks/M&P/XD/VP9/PPQ/etc are designed. You might be thinking "Ah ha! But the P-07/09 pistols are slide-in-frame designs...," and you'd be technically sorta kinda correct, but if you will look at your P-07/09, you will see that it has a metal insert in the polymer frame just like Glock and the others, and that is really what the slide rides on. All the polymer frame does it get things lined up when you reassemble. It's a loose fit otherwise.
In a polymer, it's no longer doing a real job, and at that point, it goes from being a feature to a constraint. It's good they didn't restrict themselves in that fashion.