I have heard anecdotal reports from multiple people on this, I have no sense of frequency at all and these are just anecdotes but some experience no effect at all on THC or even other more serious hallucinogens, but some do. Although this is completely my opinion it seems to me that the people that have the more profound cases of aphantasia specifically total aphantaisics who lack the other sensor recall modalities as well are the least likely to experience any effect, where the folks that score a 2 with some minimal non-usable visualization ability may experience it more, but again that’s only my opinion from what is probably a fairly biased pool of people in casual responses.