I am a hard-head to LSD, always have been (never tried other lysergamides). Just a few days ago I finally had my first full-on LSD experience. I took 5 tabs of 100ug+ LSD (3 and then 2 an hour later) and I definitely tripped, but even then there were no distortions really, it was stuff like really intense tracers randomly, things just looking "different", and mostly, a clear-headed state where I would almost feel normal and then something would set me off into a huge head-trip, for example trying to go to the bathroom and getting completely lost in the crowds, panicking, and returning (with difficulty) to my group (I was at a festival). When people describe 500ug trips they almost always describe an extremely intense experience. My friends took 1-2 each (1 took a half hit) and they all said it was really good acid.
I'm not that hard-headed to anything else, though I've done psychedelics so excessively at various points in my life that I require larger doses than most for anything but dissociatives now. But I seem to have a natural hard-headedness to LSD, and I suspect probably other lysergamides too. It's frustrating for sure.