Kosher concerns

In the SD
Hello Rabbi,
I wanted to ask you a question about a subject that I know nothing about in terms of halacha, matters of kashrut and mixtures, etc.
Many times, rabbis ban non-kosher products abroad due to all sorts of concerns.
For example, a bottle of 100% natural orange juice will be banned abroad because according to standards abroad, there is no obligation to advertise an ingredient up to 2% of the product. So you know what might be added to you. The same goes for any product that does not involve gentile cooking and the ingredients in it are kosher. Each one of them may add something else (as they are allowed) and not write it down. Or maybe the heating system is, for example, steam and also includes other non-kosher products in the same system, and everything is wasted, etc., etc.
So I wanted to ask whether it is indeed appropriate to consider all these claims in times of relative pressure (for example, someone who is abroad and has difficulty obtaining a kosher product)?