If you will expose yourself to a substance, you will probably expose yourself to it hundreds of times. E.g. if you eat mussels at all, it might be something you eat now and then throughout your life. If each exposure has a certain probability of causing an allergy to the substance, then every individual exposure has a negligible risk.
Therefore, there is nothing extra risky about making the first exposure an artificial (but guaranteed to be safe) test, if you think you might be exposed in the future for any reason. In return for a negligible additional risk, you get a opportunity to discover if you are susceptible to an allergy before ever trying the substance. What am I missing here that leads to your advice of not "getting any unnecessary allergy tests"?
There are many cases that come to mind where someone has not been exposed to a potential allergen (growing up being sheltered from it, childhood aversion to it that was never reassessed in adulthood, simple lack of that allergen in previous environments) and I think it’s fair to want to avoid someone suddenly having new allergic reactions, especially when those reactions can “suck”.
Therefore, there is nothing extra risky about making the first exposure an artificial (but guaranteed to be safe) test, if you think you might be exposed in the future for any reason. In return for a negligible additional risk, you get a opportunity to discover if you are susceptible to an allergy before ever trying the substance. What am I missing here that leads to your advice of not "getting any unnecessary allergy tests"?