I ONLY use manual (to get there, hold the manual button down several seconds, until the manual light lights.
I always fully dump all the air first. Then lift the front until it rises an inch. Then lift the low side rear until it indicates level side to side.
Then lift the high side rear until it touches the ground.
Then touch it up. bing, you are level.
I use a round bubble level on the floor where I can see it.
Powergear's "set level" procedure is not difficult, download the instructions as stated above. But it still doesn't seem perfect and doesn't hold. easier for me to just set the bubble level on the tile.