Update on my OZ9 extraction issues.
After having numerous FTE's I replaced the extractor with a new Glock oem extractor but the issue continued. I installed an a new entire extractor assembly and still had FTE's. A call to Zev and a conversation with a very helpful rep may have fixed the issue.
The rep offered that Zev has found the OZ9 extractor is a couple of degrees off from a factory Glock. The slight angle change requires more tension on the extractor. Zev sent me a new extractor assembly which they claim has been redesigned to increase tension for more positive extraction free of charge.
Unfortunately I did not mic the original and new assembly to compare the oal and determine what was changed. However when installed the new assembly protrudes a fair amount more out of the rear of the slide requiring a little more effort to depress it to slide the back plate on.
I've only shot 50 rounds through the OZ with the new setup and so far no issues, I'll keep my fingers crossed.