> in Amsterdam where mushrooms are legal, the shops are quite careful to ensure they are giving you the rundown on what to prepare for, dosages, finding a comfortable and reliable setting, safety, etc.

Last time I was in Amsterdam was quite a few years ago but... magic mushrooms were illegal. Instead they sell psilocybin truffles so roughly the same thing. When I've bought them, from a few different popular shops, no words of caution or safety were exchanged.