Okay, while we still have lots of time, get your rigs out in the mirror and practice your mag changes; FAST!

Actually SMOOTH! Since Smooth = FAST!
Smooth draw out of the holster while your AR is slung around your torso (single point, right?), RACK the slide and engage target. Do that again!
Place ALL 4 or 5 mags back in the vest pouches and cycle them through the gun again... in front of a mirror. Now you understand that nicname "mirror kommando" ???
Then do that same drill with the pistol magazines (all 2 of them)...
I'm not joking! Nobody is gonna look at you. Ensure you don't drop your mags on the engineered or laminated hardwood floor, place an area carpet/rug/prayer rug on the surface to protect it from magazine dings!

Well your partner might look at you and yell, "Put down your purse and rack that pistol like a man!"
Who knows if your partner has been watching my YouTube vids with the stale jokes?
Keep practicing all these mag drills before the clinic. You will be glad you took my advice!
Cheers,
Barney