Don't worry, you might be overthinking it. The SN failures from here were almost all because they were found early and hospitalised. Even if you vomit, there's still a very high chance you'll be successful.
I've managed to get some meto but I'm not sure I'll even bother taking it since it apparently reacts badly with my Lexapro and I don't fancy brain zaps and muscle spasms. I'm just going to have a back up glass.
I don't think it's anything to worry about, looking at all the previous reports from here.