Will just have to see how much evaporation there is I guess. 16 Qts. in this cooler the way I have the item in the cooler puts the water level right in the middle of min & max indicators. I guess it will only be an issue on long cooks. It shuts off if the water drops to low, so I cant burn it out that way.
I am cooking this beef for a couple of hours, so that will not be a test. But I will leave it on all night and see where the water level is in the morning! I find it hard to believe that a 1/8" gap can lead to that much water level loss, but that is what experimentation is for!
Worse case scenario I will stuff some wet cotton balls in the gaps!
The min and max levels are pretty close to each other, and the hole yer making won't be too conducive for water/heat retention. Yer gonna get evaporation if I interpret what method yer going to do.
If I read your post correctly, yer going to make a hole that allows the clip to be in the cooler? Sounds like a bad scenario in the long run.