I feel like I'm the only one on the planet that has absolutely no issues with inefficient headphones that require speaker amp levels of power.
Nah, you're not the only one. I don't mind inefficient headphones. The fact is, the HE6 is an inefficient headphone - so coming into the thread about the HE6 and complaining that it should be more efficient is like going into a Sennheiser thread and complaining that the headphones leak too much sound so they should be closed instead.
If you want a "more efficient HE6" - you want a different headphone. And that's fine, there's plenty of options out there for efficient headphones (from Hifiman themselves as well). At the end of the day, it's simple. You want a different headphone. Move along. This one is inefficient.