Incidentally another way of doing it is to squeeze the bushes using a press or a vice, effectivly reducing their length and making them fit, however the bushes will eventually expand within the subframe and there's your pivot bolt torque setting gone for a ball of chalk. Any method that requires excessive brute force during assembly
will introduce stresses for which the suspension has not be designed.
As for 'not trimming/fitting' I'd like to see the documentation and research to substansiate this claim. Or is this just an opinion?