If you need any further evidence, my son’s sum total of engineering ECs was math club. His experience “building” things stopped pretty much with Legos. He’s now a mechanical engineer.
BTW, if you want the most benefit from this forum, you need to engage with your own thread.
Good luck!
P.S. @Gumbymom knows more about the UCs and CSUs than most posters out here. As far as first gen and socioeconomic status, at least at Cal Poly, it is taken into account in a very circuitous way. First gen per se, gets you nothing. You are only given a boost if one parent or both parents did not finish HS. Low socioeconomic status is only taken into account indirectly, sort of through assumption, if you go to a Hayden Partner school. Other schools use different criteria and at least a couple of the UCs are “holistic.”