I’ve been using this trick for many years. Things like when in a car park and trying to confirm I’ve locked my car at some distance, this has worked. It’s been pretty reliable for me.

One more anecdote, this has not consistently worked for me. Raising the height of the receiver may have an effect but I'm not sure.

We need to cross analysis people across the axes of tall/short and large/small head for posterity

Tall with large head here, works pretty consistently for me

Maybe there's a difference in resonance of the people reporting their experiences here; also differences in the frequency tuning of the fobs?

Maybe the one case where "you're holding it wrong" is valid advice.

"Works on my skull"

I typically press it firmly against my chin, and I have observed increased range many times (including testing this trick explicitly with a few different fobs a few years ago out of curiosity). Try pressing more firmly, or rotating the fob.

I too have been using this trick for many years on many cars since first seeing it done by Clarkson on Top Gear (circa 2006 IIRC and linked in the PSE question). I still baffle people with the considerable amount of extra range it can achieve. Half a football pitch was probably the best example I got on a 2008 Nissan Qashqai.