Press command is issued when there is no visible movement of the bar on your chest/abdomen. This includes any teetering left/right after it settles. If you bring the bar down slow, judges will issue the press command quicker than if you let the bar fall on you or let the bar sink into you.
I can't think of a good reason to do paused bench unless you compete or plan on competing.
Did my first meet yesterday. Went 8/9. Totaled 827 at 163 bw (which is skinny as fuck for being slightly taller than the king of manlets). Obviously not impressive but now I have something to work off of.
TILThey aren't better than Rehband per se, just different. Might get a few extra pounds of rebound out of the SBDs vs the Rehbands. They became a thing when they became legal for raw competition where sleeves are allowed (e.g. IPF)