wow, that's a lot of pharmacology! I have done just a bit of tyramine research as a result of doing MAO inhibitor research. Mono amine oxidase inhibitors block the actions of various enzymes in the body allowing certain compounds to enter the blood stream unaltered (tyramine being one of them). In addition this enzyme inhibition increases the level of the neurotransmitters dopamine and serotonin.
Thus, MAOIs are often used as antidepressants. I don't know names for lab created ones, but herbs like St Johns Wort, Yohimbe, and Syrian Rue are all MAOIs. And foods containing tyramine should not be consumed for a couple hours after taking these (time will vary with dose and strength of MAOI).
Unless consuming one of these MAOIs, you should generally be okay to handle moderate amts of tyramine; and I'm sure everyone has varying sensitivity to it - it does seem to be a vasoconstrictor. Avocados don't seem to give anyone major problems, but for some seem to be not entirely ideal. I would hesitate to lay the finger of blame on tyramine just yet, maybe just a finger of blame.