You do not need to be perfectly level for the fridge to operate efficiently. If you are comfortable so is the fridge.
I used one of those blinking light level indicators to set the coach but most times will eye ball to fine tune if I want. Finding a flat true surface in the coach to use as a master level reference can be difficult but fortunately you do not need a high degree of accuracy for the various mechanical systems to operate. I've intentionally off set the coach a few times to get the A/C to drain the direction I wanted.