I just looked at the JBL website to view the description of the "Reaper".
"Product Description
The sear lever looks thick enough, I wonder why they used plastic for the other levers unless they were concerned about how the gun floated. A trigger can be slimmed down away from the load bearing areas if it is cast rather than cut from plate. Any photos of the levers outside of the mechanism cassette?
You mean why did they make the trigger itself out of plastic? Not sure, but could possibly be to eliminate galling? On "that other forum" Majd has talked quite a lot about that happening in a lot of triggers he has taken apart. Also, if I got the timeline right, Sporasub's fix for an uneven trigger on the One was to change the trigger to a plastic one. Even the Abellan trigger which is supposed to be very nice has a plastic trigger.
(Apologies if I misunderstood the question:))