Lived about a quarter of my professional life in Africa - mostly we made our own hot sauces. (Gotta do something to gag down the manioc.)
I'm amazed that you can find Vegemite in Kansas. Beloved Spouse is from UK and we generally stock up on Marmite when visiting the family. Marmite on the hoof!
Won't argue as I don't like either. South African Monkey Gland sauce is another, if vilely named, alternative. And yes, Lea & Perrins sauce is better than the generics.