hello99 -“The physics of a microwave makes it extremely likely that the steam pressure will burst any wrappings.
if it doesn’t burst, you’re fine. I don’t recommend it because it is a risk. If only a small amount of steam is escaping, it may not be a problem”
I don’t see what you’re afraid of because you posted above:
“Anyways, a liquid heated for more than a minute or so DOES make the roof of a microwave hot.”
If it bursts this usually happens right before the ending time -so how would the roof get hot?