I think the higher grip on these guns cause your finger to engage the trigger at a steeper angle, resulting in rubbing against the bottom of the guard.
My HBI trigger helps due to the shape.
That doesn't explain why only SOME guns (both in the hammer-fired group and in the striker-fired group) have the problem.
I've had MANY CZs over the years, but never experienced trigger bite until I got a P10c. That P10C, which I got in trade was my first experience wit the behavior, and shooting it was actually painful. (In hindsight, I suspect that was why the guy I traded with wanted the to trade it away.)
While installing the HBI Trigger did reduce the trigger sting substantially, I now realize that it's still there, just greatly reduced. During my last range session earlier this week, the "sting" or "bite" didn't start to make itself felt until about the fourth mag of the range session. The more I shot the gun, the more aggravating it became. (I don't think the sting was getting worse the longer I shot the gun; instead, I think I was becoming more aware of it's presence. It felt as though some vibration was stinging my trigger finger wit each shot fired.
It seems to me that if trigger shape (and how the trigger finger presses it) was a factor more people would be having the problem. I first heard about it trigger bite 10-15 years ago, when I was one of the moderators here on the CZ Forum. If I'm remembering things correctly, most of the complaints came compact decocker-equipped CZ shooters.
I'd like to understand WHY only some guns have the problem, when the internal parts are mostly the same in most of the hammer-fired CZs. With the striker-fired CZ P10c, the internals are ALL the same.