@justme22 im not sure comparing it with a lethal allergy makes sense here though. There are many situations dealt with in the gemara (or could be elsewhere, but anyways), that talk about an occurrence where someone accidentally had treif, or something along those lines. I recall it not being an issue if the person did not ENJOY it. As far as I understand, it’s assur to ENJOY eating something that is non kosher. Therefore, since someone with allergies does not actually taste whatever substance might have been on that utensil, I don’t see the relevance here. For someone who just does not like the flavor, if they don’t taste it, then there is no issue. I feel that the same thing could be applied for our kashrut situation here, where if we don’t taste it, we therefore don’t enjoy it, and it should therefore not be an issue.
BTW this is just me explaining my logic and thought process, and wanting to discuss it, I am not saying any of this implying that I am right and everyone else is wrong and this is how it is. Clearly it’s not black and white. 🙂