I'll post it here like I've been posting everywhere else.
The gas regulator was never the issue. Study the 807-trials & testing, and watch the early, Pakistani promotion videos. The Bren 807 / Bren 2S / Bren 2Ms in 7.62x39 were always over-gassed, and normal ejection was 1 - 1:30, per the engineers who designed it.
My Bren 2S was used by HBI to solve the FTE issue, and was used in the creation of the HBI piston spring & suppressor gas-port sizing. They found the problem, within a week, which was the ejector spring channels of the bolts, had metal shavings & debris left from the factory. This caused the ejector springs to bind, not allowing the ejector to fully extend, and with the very over-gassed nature of the firearm; only highlighted the simple QC issue even further.
Prior to HBI solving the issue with my firearm, and multiple others in their possession they used for testing, I couldn't fire a string of 5-rounds without an FTE.
To date, I've fired over 2,500 rounds without an FTE, both suppressed & unsuppressed, brass cased & steel cased ammunition. My Bren 2S still has the original, prototype piston spring, which the production spring was an improvement.
Hopefully this has helped someone. HBI did not release this info, in my opinion, because likely CZ-UB / CZ-USA did not have the capabilities of handling a mass recall with no spare parts on hand. Just speculation, but likely not far off.