Aww glad you had a sighting of Koppi
I seen my reclusive Jaska today for the first time in quite a few days too.
The deep bedding does make it easier to hide away and especially when they are so small they can move about at the bottom without even distrurbing the top layers of bedding making it hard to know what they are up to and where they are. I agree with the others, I think it's a personal choice as to the less or more substrate, I think it would definitely be worth a try though if you wanted to have a routine with her