Tasty, I couldn’t find a place it said the bag would blowup on you or that it was harmful. Just simply wasn’t tested or approve for that use.
With today’s liabilities and cost of testing a product it could simply be not worth it to the company. Some one asked them if they could use it for boiling, they had to say read the label.
I can hold mine for 3 hours, after that you are pushing it,  the skin gives out and they absorb water and lose flavour.
Not that they aren’t edible. Maybe the plastic would protect it a little longer.