I remember when the 4-sub-tryptamines were first available, everyone thought the 4-AcO esters were all simple prodrugs of their 4-HO counterparts. Our Big and Dandy threads were even combined together for 4-HO-DiPT/4-AcO-DiPT, etc. Some people were saying that the chemicals differed, but a lot of people dismissed it out of hand. Then 4-AcO-DMT came out, and pure 4-HO-DMT was available for a while, and myself and some others got to try both, and for me, the difference between them is profound, I am 100% confident I could easily discern which I was given in a double blind test. It seems that 4-AcO-DMT DOES convert to 4-HO-DMT in vivo, but my theory is that it happens at different rates in different people, so that more or less 4-AcO-DMT is unchanged to cross the BBB itself depending on your individual metabolic factors. For me, 4-AcO-DMT feels like oral smoked DMT in the first phase, it's a totally different feeling from 4-HO-DMT, though in the second half of the trip they become much more similar.
I bring up this example to suggest that I think we know less about how these drugs can work as prodrugs than we sometimes think we do. I would not be surprised at all if a similar thing is going on with 1p-LSD. Some people may easily cleave off that 1p and find the effects indistinguishable from LSD, while others may cleave it off more slowly and more 1p-LSD crosses the BBB unchanged. Not sure if it's true but I am as sure as I can be that it's true with 4-AcO/4-HO-DMT.