Trying to get into the run, but I can't find consistency of when I'm allowed to skip a cutscene if any. When are you allowed to skip a cutscene?

I've tried to find guides for this but none of them show how to do it where you launch forward instead of sideways. The biggest example is at the start of Semper Fi after the assault starts and every run is of someone flicking their mouse to the right and then up. I've tried it on runs but I haven't figured it out yet. What keys do you hold/let go of to launch forward.

The request is for my full game run and my question is that did I get time added to my run because of my stream starting late?