Totally possible. I believe from the last time I looked at it, about 30-40% are "non-responders" in the sense that you can get some more force production out of using it, but the health and bioenergetic benefits of using it are fairly well documented. And it's cheap. I'd keep it on my playlist if I were you.
Ahh. This is gonna sound super nerdy, but I just add my bcaas to an empty nalgene or water bottle while it's on a food scale and see how many grams I've got. Since it's pure bcaas, 5g=5g, ya dig? Other than that, a rounded tablespoon is more than enough. Not like you're going to OD on it either.