I found this thread too late. I didn't notice the set screw backing out until I experienced a misfeed.
When I discovered the problem, the loaded chamber indicator pin and spring were nowhere to be found.
Fortunately the plate and retaining screw were still on the gun.
CZ Custom does not have these parts available, and referred me to CZ-USA.
CZ-USA didn't want to send me the parts, they wanted me to send in the gun. Turn around time... 4-6 weeks.
CGW... Sure, we have the parts. Yes, you can install them yourself, it's pretty simple. Let me get those out to you.
Three days later the parts arrived. Installed in about 10 minutes. If you know what you're doing, you'll probably do it in 3.
Blue loctite on the set screw.
Great customer service by CGW. If some parts don't show on the web site, give them a call. You might get lucky.
It's a great day.