How much of a difference do your preliminary tests show? There are a couple of things you might have missed, for example, not having to charge a shinespark after the two worm enemies to break the blocks to enter Ridley. You're also best off grabbing the missile tank there when heading down.
My preliminary test was just running from the exit of the Ice Beam area to Hi-Jump through the Ridley First Shaft and not. Like I said, very rough. It was a ~5 second difference in favor of the normal route. But you're right, I might have overlooked some things. I feel I'm going to do some more thorough testing in the coming days, stay tuned.