I think the short answer is basically yes, although there’s some nuance. At a basic level what happens inside us is chemistry and physics and one way to measure gross efficiency of any system is how much power is “lost” as, you guessed it, heat. Whether it corresponds to RPE I expect is less straightforward.
I recommend you check out the empirical cycling podcast, in particular the series about Vo2max. I caution you it is a very deep dive, but if you’re asking these questions, it probably means you’ll be into it 