I certainly agree with that, particularly when hot smoking. I gave up on the water pan in the MES very soon after getting it!
First things I think of when people put water or open ice cubes in a smoker is an MES. If you do that with an MES, you add too much humidity into a smoker that holds heat & humidity so well
An MES works much better without adding more humidity. That's why I use a jug with about 3/4 full of frozen water. No Humidity added.
The humidity also makes it harder to keep an AMNPS smoking.
Bear
In the case of this cold smoke of the butter, the ice hardly melted, and the cool temperature in the smoker didn't allow a lot of evaporation. BUT, it still would have been nicer if I'd have had some already frozen bottles of water. In this case, I had to use what was on hand.
I could have covered the tray with foil to seal it in, but it never became necessary in this particular instance.
I need to clean out enough space in one of the freezers to be able to freeze a few jugs of water to have on hand in case I need to cool down a smoker in the future.