Synchros do not work when at a stop and shifting into any gear.
They most assuredly do. What happens when you shift a non-synchro trans from neutral to 1st gear at a stop without waiting for the input shaft to coast to a stop?
OH nothing John, just RAM it in, and generate some FLAKES to seat the bearings and parts, Makes for a smoother shifting trans when no teeth are left on the gears.