Lots to think about in this. I only change springs when I notice a lack in performance. The brass flies way across the range long before the gun is unreliable. That may be 400 rounds of full power 40 S&W SD loads, or 2,000 rounds of 9mm practice loads. I'm not sure where you are in there.
It's a specialized gun, as you said, the price is not the concern. If there is a concern about reliability because of the spring, before it is launching brass to the skies, it might be worth having CGW or customer service giving it a once over.
My personal views:
I don't change springs between practice and carry. I want it to shoot in real life the way it shoots in practice. Of course, it should be reliable, and I replace the springs when it is no longer enjoyable to practice (i.e., when brass is bouncing off my head...
).
I do not think of it as a design flaw, more of a compromise. The springs are 'under-built' and wear 'prematurely'. But in doing so, you get a smaller size and less weight. Look up the development of the Sig 225. By RAMI standards, it's a pretty big gun, and only designed for 9mm, and they still had problems with recoil spring failure. I feel like I'm replacing springs in my AMT Backups every other time I go to the range. So in my mind, the folks at CZ did a pretty good job.