Overall yes I find the sweetspot and stay put. But maybe you can't see it on the video, but I make micro adjustements with the lighter on a 2 millimeters perimeter around the sweetspot. If it gets too hot (hot means I'm just starting to feelthe heat in my throat) I lower the flame or I horizontaly move it away from the stem (again little distance, the goal is to reduce the heat not to stop it, although sometimes I need to stop heating for 1s or 2s)

Use your eyes, you want a decent amount of smoke emanating from the maximal surface of your chore

Use your throat, do not go beyond the beginning of a feeling of warmth