I’m also a MT driver. I’ve driven my fair share of AT’s though. With an AT, it’s always pushing forward, so the brake is actually working against the idle force of the engine, so simply releasing the brake causes forward movement.

I too sit at most lights while standing on the clutch and brake while in first. It’s the MT “ready to go” stance to me. For very long lights, I’ll kick it into neutral and take my foot off the clutch, but for the most part, in active traffic, I’ll just stand on it, because the light usually isn’t long enough for me to reposition that much…

It’s far easier to do as you say, as a veteran of MT driving, newbies will struggle, as they do. To be fair, I’d do the same as you, but I’m still very pragmatic about when I do it.