I still think trailing assigned seat numbers on flights is worth ago.
Apparently they trailed it but only on practice runs not actual operating flights.
My previous airline had assigned seating and especially on airbridges it does help as you board in sections back, middle, front.
Also it helps to stop families moaning at crew cause they got on last and cant sit together (out fault as usual, not the fact that they should have been at the gate in good time), Plus when we then try to arrange for them to sit together that takes up more time.