>>12684804I think besides a bachelor's, college education won't help you much with industry, or even with grad school. What it will do is broaden your horizons and help pick up intuition and learn faster.
I know you asked for STEM minors, but if you're already in STEM, I'd consider English. Writing is a crucial skill in industry, and your writing would be significantly better having been in English/Lit courses. It'll also make you somewhat more erudite. Otherwise, CS would be good for simple scripting tasks which are in demand these days. Statistics could also be useful, it's almost a universal skill.