Thank you for that. I understand it's a minimal risk as you said but my BP has no problem eating outside her enclosure.(though I know many snakes do)
All I was trying to do was warn the OP of the risk(minimal as it is) if they use aspen substrate.
Hell I got LUCKY with our BP Snickers! She doesn't mind eating outside of her enclosure, has never hissed at us or bitten us and in spite of our months of poor husbandry and a bad shed(all that is corrected now) she forgave us and isn't mean in the slightest.
We are "LUCKY" to have such BP with an AWESOME ATTITUDE but I do understand in the end we did just happen to get "LUCKY" with Snickers.
That being said I feel I had the right to warn the OP of minimal risk of impaction which is all I did and thank you for understanding that when others failed to.