Without cutting open the bottom of the GF, you are limited to a maximum of 2" total depth.
Do you have a good source of tumblers or flasks that are under 2" in diameter? The thinnest one in my collection is still over 2.5", so it wouldn’t even fit under the GF laser by itself, let alone with any kind of rollers under it.
A device for turning pens, rolling pins, other small items… that could still happen, if not by GF then by someone else.