A combination of boredom and curiosity after reading the P320 bent ejector thread led me to do some further experimentation on over-insertion. Here is what I did and found. Note that these were done with a 140mm mag (p-09 with springer precision baseplates) which holds 22 rounds:
1. First i removed the slide and slammed an empty 140mm mag into my p-07. I found that during a normal insertion with i-need-you-to-get-back-to-going-bang-now force, the magazine does not ever contact the ejector. However, by slamming it REALLY hard I could get the magazine to overshoot the mag catch slightly and push up on the ejector. this could be remedied by pulling down on the magazine a bit so it seated in the mag catch, at which point the ejector would spring back into its normal position. I did this a handful of times, very aggressively, and didn't notice any type of wear on the mag or ejector.
2. Next I replaced the slide, and did the same thing with the slide closed, with the 140mm mag loaded to 21rds (fully loaded to 22 there is some resistance when racking the p-07 when the mag is seated with normal pressure). I could not induce anything unusual seating the mags aggressively from a normal reload position. Then I adjusted my hand position to gain maximal leverage (not a natural reloading position, gun very low on body and magwell over 90 degrees to left), and really slammed a loaded mag in as hard as I could. I found that when doing this, it was possible to actually slam the mag so hard it pushed up on the ejector, which in turn pushed the slide slightly out of battery. Unlike in the no-slide experiment, this time the recoil spring pushed the slide forward, returning the ejector to its normal position instantly. The gun could now be loaded and fired normally.
3. Next, I did the same with the slide open, using the 140mm mag fully loaded to 22rds. Using maximal force I was able to get the fully loaded mag to push up on the ejector. This did not prevent the slide from releasing normally and chambering around using the slide release.
4. After doing the above, i field stripped and examined for any unusual wear. I didn't find any, and the gun loads, ejects, etc. normally. Unsurprisingly there are some not-insignificant marks on the casings from being slammed into the ejector.
In conclusion, I think the CZ P series is pretty much immune to parts breakage or stoppages from over-insertion of magazines. I really appreciate the inexpensive and easily replaced small parts used in this pistol. They make it easy to work on and also fun to experiment on because you don't need to worry about making an expensive mistake, as you would on certain other popular handguns. Pretty much the only part besides the serialized frame that would be a bitch to replace if damaged, would be the steel frame inserts. And I'm not sure how you would damage those.