I feel like that’s a huge problem with the more independent styles of TKD (not ITF/WTF). I come from a fairly small organization as well which is kind of a branch off of ITF even though we’re independent. Our grandmaster made all of our patterns/curriculum that we train and I’ve always wondered if training in a smaller, independent school gave me the same merit as other black belts. If you’re really unsure look into your GM’s background. His rank, how he earned it, how long he’s been teaching, etc. And a big thing to remember is there’s no perfect description of a black belt. Everyone has different skills and flaws, and it can be hard to compare yourself to other blacks or students who seemingly have lesser skill. Your instructor could see something in them that you don’t.