My comment said "a little tongue-low is OK, but never tongue-high." I said that because it is nearly impossible to get your trailer perfectly level. With hitch shank adjustments being made in 1" increments, one position might be a little too high and the position below a little too low. Given those two choices, choose the one a little low. That doesn't mean to intentionally set up your rig tongue-low, but opt for that if you can't get it perfectly level.
2015 Jay Flight 32RLDS Elite
2012 Chevy 2500HD Crew Cab LTZ (6.6L Duramax/Allison)
Equalizer Hitch (1200# bars)