minecart furnace switching place between the other minecart with is pushing

yes i know it's he old bug but size the last minecart improve experiment one minecart are bind to the engine in foward mod instead of the backward mod it's he little bit arder to pass he slope for he train, maybey remouve entirely this binding mechanics entirely or reverted it to the backward mod only egain (also the old way is he little bit usefull for train module)?