That’s how I run my table. I am a merciful god, but also a petty god if you reach for the heavens a little too hard. D&D magic already screws with thermodynamics to the point where free energy just exists, so I try to draw a line just short of where anyone figures that part out.

In the back of my mind, I’m always asking the question: “Why wasn’t this loophole exploited in the world already?” That usually prompts a suitable response.

you’re basically doing fantasy electrical engineering with vibes and a screwdriver; ask yourself, what could go wrong?

Exactly. In the situation that OP raises, I ask myself: “Does Newton or Gandalf win this argument?”