But aren't those exact hinge assemblies, and maybe poor construction, the exact reason for this SB?
https://www.vansaircraft.com/pdf/service_bulletins/sb14-02-05.pdf
It certainly looks like this fix is spreading the loads over a larger area.
My suggestion was actually for a standard AN960 washer to get 50% more bearing area over a straight nut.
Is not properly torquing jam nuts a reason to change the design?
If that was done for every detail that people make mistakes on we would have to stop using the total performance description because that weight gain would make it no longer relevant.