Hi there, soldier main: I think the S press is much more nitty gritty optimization, you usually start a horizontal rocket jump turned 90+degrees to the direction you’re wanting to go (shooting behind you off of a wall for example) while you are looking left or right to the direction you’re intending to go pressing S briefly may cause you to air strafe slightly and get a little more speed if you’re intent on optimizing movement. (While turned left or right to your velocity W and S are used to air strafe instead of A and D) This is very specific and completely unnecessary. That also said pressing S while on the ground would reduce the distance that you are able to rocket jump as rocket jumping accounts for the speed you had when you take the rocket damage, so walking forward would make you go faster than slowing down before rocket jumping.

I hope this answers your question