Just because you have not had an issue means nothing(You didn't even state what kind of substrate that you use)
And if you do use Aspen substrate there is a vast variety of them as some of them are shredded and others are sharp chips and some of them are "dusty" and others are not.
I am just giving counterpoint advice to the OP because the OP didn't state what type of substrate is being used.
You can insist all you want that it's better to feed inside the snake's enclosure(my snake has NO PROBLEM eating outside of her's though) but in the end if you do feed inside the enclosure you better make sure sure you are not running the risk of compaction!(and if people use shredded newspaper that isn't a problem)
Aspen is what i use. Like i said in a few other posts if have 50+ snakes and to think about moving 50 snakes out to feed i would be there forever... You have been lucky. But again how many snakes do you have to feed every 3 days to a week...