With respect, you may have misunderstood my comment in that my use of 'non-foodsafe' plastic brewing equipment was done because there was nothing else available at the time. It was not a deliberate choice, but it appears to have done me no harm. However I am not suggesting that people should do the same when nowadays there is an abundance of food safe brewing equipment.
Even so I often see posts on here where people get overly concerned about the possibility of barely measurable quantities of plasticer being leached into their beer, yet they have no qualms about consuming significant quantities of alcohol which, over time, is known to present identified health issues, including addiction and organ damage in extreme cases.
So in the case of the OP the potential risks associated with using a small non foodsafe plug to seal an undoubtedly foodsafe and much larger plastic container should, in my view be balanced against the relatively much greater alcohol risk from the beer within it.
Finally in relation to your smoking vs. cancer comment, years ago I smoked all sorts of tobacco products when it was not deemed to be much of a health risk, but when the evidence available increasingly suggested I should stop, I did so.
