I use Alton Brown’s method, which is quite similar. Make it directly in a stainless steel mixing bowl with AL foil covering the top, with a few holes punched in it. Agitate it over a burner, stop when the popping is done. Salt and butter (if desired), eat right out of the bowl after it cools just a bit.
My favorite for popcorn; was using an old wok. Made the BEST popcorn - quickly - and in large amount; with little risk of burning any of it. Don't know if it was the shape - or material. Whatever- it was the best popcorn 'maker'/lol
One more point per popcorn preferences; WHITE kernals are the best and sweetest; IMHO. And yes; if butter added; then use the real thing! Authentic 'anything' better; than synthetic or mixed media oils; so to speak. . .