I never said it was fully safe, nor did i encourage doing it, i just oppered this is a huge improvement over just taking untested tabs wich sadly the majority of people do or had a phase of doing. There is obviously rare exceptions in wich case this could get dangerous or very unpleasant, i hope i made that clear enough in my message cuz i definitely dont wanna encourage unresponsible usage.
The bad trip description you gave is more likely then on acid, it can have more gnarly sides if your prone to it for sure, however most people on a normal dose of NBOMe will have a fun or neutral trip, i know in the netherlands where i live wich has an incredibly transparant and clean black market, 17.5% of acid found on the street contained NBOMe. Its pretty assumable that number is much higher in most other places yet you rarely hear of people who went trough those typical vasoconstructive and intoxicating effects 25x-NBOMx substnaces can have. Its not in a dealers interest to give you a overdosed tab and the majority of - mostly new trippers who arent familiar with the effects of LSD yet, will not even realise they had a NBOMx substance