Guy who rose through the ranks from guard to site supervisor here:

If you want to rise within your current company, basically, skill + experience + initiative + nepotism = promotion. I'm qualified for my job, but I got both of my major promotions because I knew how to ingratiate myself with my superiors, how to talk about our common interests, and happened to be scheduled such that I could talk with my superiors casually frequently. The fact that I'm competent as a supervisor was noticed only after all that.

Initiative means dick if you don't connect personally with a superior who can influence your promotion. After you've got that in, then your initiative becomes diamonds.

Also, someone needs to retire or die for you to have somewhere to advance into.

Your best bet if you're impatient would be to apply for supervisor jobs for other companies using your security experience as an in.

$800 correspondence Security course

I'm trying to hire assistant supervisors now, and I'll be honest: certs don't mean dick to me, unless it's something required to be hired by us.

I look at whether your employment history shows signs of job hopping, how you handle curveball questions during the interview (because srsly, 9/10 of what you're going to be doing is making quick judgement calls to either solve tricky situations, or answer employee's trick questions), and whether or not I actually like your demeanor, because ultimately, I'm not going to hire someone that a) I'm not going to like working with and b) my crew isn't going to willfully take orders from.

your cert is just something I can derive trick questions from to see how you answer fast paced questions on the spot.