Would a 2 or 2.5 gallon bucket work better?
For something that small YES, but I can see using the 5gal for a whole brisket if I ever do one that way....
The MAX line on the Inkbird is really only about a little over 2" below the rim it clips on... so I had a 5 gal filled to within about 2.5" of the top to start with, then it lost about an inch in 10hours of evap...
SO that was way more water than I needed for a 3lb corned beef, but again, something 3 times that size would need that.