I have about 4000rds fired through this gun, and I have never removed the extractor. It holds an unfired round very firmly, and vigorous shaking with not dislodge it. Will an extra power extractor spring make this C100 run anything at 100%, or will it cause other problems? Here's a cut and paste from CZ Custom about using an extra power extractor spring: Extra power extractor springs are available for the CZ-75/85 series pistols - all calibers. 25% stronger than factory springs. We have never found it necessary to use these in 9mm pistols and often result in feeding malfunctions.
Over the years, I've replaced the Extractor Springs on around eight Cz and Tanfoglio Based Cz Clones without issue, but I've NEVER used Extractor Springs from the Cz Custom Shop.
I've only used the Wolff Extra Power Extractor Springs, and these have been available for quite some time.
Again, I've had to trim them to fit and I recommend allowing only two coils past the length of your original Spring for length.
Typically, I've only ever had to trim off one coil. The Wolff Extractor Springs come a bit oversized to fit both Cz97B and the other Cz Pistols.
Side Note: Also, consider honing out the Extractor Pivot/Retention Pin hole, just an eeensy little bit, while you have it apart.