Oh yeah, I forgot a bit of plastic disconnector trivia in my last post ...
In my last armorer class (2010) we were told that there was some discussion occurring within the factory about maybe going back to the steel disconnector, but the reason wasn't what you might expect.
As it turned out, while the plastic disconnector did great during endurance testing and normal
use in the 3rd gen guns, their "Achilles heel" was .... armorers.
Since the disconnectors in the TDA guns have to be carefully installed and removed by shifting their tails around the drawbar disconnector tab, which involves using a pin punch to move the tail around the tab, it was observed that an inattentive, inexperienced or "rushed" armorer might push against the tail of the disconnector too hard, at the wrong moment, and break it off. It didn't happen during actual live-fire ... but during armorer inspection and detailed disassembly while repositioning and pushing on the tail.
The "read between the lines" comment I heard expressed was that they'd discussed trying to make steel disconnectors again (but with better dimensions and tolerances than the old ones) in order to make them less susceptible to damage by armorers.
Dunno. Maybe so. Funny, though.