Syephen prayed to The One Who is alive forever more, the ONLY mediator between man and God. Not conflating, though your reasoning may see it that way ... the exclusionary fallacy, maybe?
Whence, btw, the doctrine that those in Heaven cannot even hear anything down on Earth?
Even when I was an Evangelical, I'd never even *heard* that one?
It seems the essence of the "less filling/tastes great" conflict is the idea that asking Saints to pray for you is akin to idolatry ("there is *one* who is able to save") vs. "man, the more people praying for me, the better" with tinged of "imputed righteousness" and " the prayers if a righteous man availeth much" (see also Ezekiel 14:14 "...even if these three stood before Me...")