Bollocks.
To quote https://www.thevespiary.org/rhodium/Rhodium/chemistry/doisynth.html (https://www.thevespiary.org/rhodium/Rhodium/chemistry/doisynth.html)
:
'The iodine/silver sulfate system has now been applied to the syntheses of iodomethoxy-amphetamines. [...] Protecting the amino group is not necessary under these conditions, and high yields are obtained.'
Reactions yielding ~5g of 2C-I are perfectly feasible.
Firstly: Post 464980 (https://www.thevespiary.org/talk/index.php?topic=7335.msg46498000#msg46498000)
(Antoncho: "Iodinations of 2C-H/2,5-DMA", Chemistry Discourse)
Secondly: Should I type it once again, after Antoncho and Mescalito? Well: in mescalito's experiences the freebase-amine was only once successfully iodinated - the first time, and we have never succeeded in repeating that experiment. In all other attemts we have made the aminogroup was not removed only if it was protected by protonation.
That is practice, something SWIM have seen with his own eyes and not a reference to some publication (even if it is by Shulgin) or a doubtful hypothese the Big Hive is being full of.
By the way, amphetamines seem to be more stable in theese conditions, than PEAs (again, see the reference above).
Reactions yielding ~5g of 2C-I are perfectly feasible
What about 25 g? 5 g is too little, you know ;)