While I've never seen the need to do that - I've never had an issue with just laying the probe wire across the drum (bowl) and setting the lid down on it. But, I have also seen a lot of people use that method on WSMs and Kettles without any ill effects.
For some it's just a matter of making that first cut or drilling that first hole. Once you commit to it, there are dozens of modifications/improvements you can make on the basic design.
BD