Too high evaporation- add back a gallon or so of water after 60-75 minutes
Can't read volume- make a measuring rod/ stick , mash paddle
Won't sit flat - put the barb in only when you want to use it, or shorten it if that will work.
+1. also could partially cover your kettle, and you could reduce the heat input, once you are at boiling, the higher the heat input the faster the boil off and vice versa. you should be able to control this with a gas burner.or electric with a pwm. i have a 1500watt element. slow boil off. if i put in a 2000w element, without a pwm it would just get boil faster and boil off more water.