The one piece Bonaco lines are not going thru the side panel very well. Even with rubber grommets they will rub on the edges. Brett from Bonaco suggested I install a fitting and use two piece line.
So, I ordered the fitting.
I struggled with how to mount the fitting on the double wall. I tried lots of washers and crap. Bottom line is you have to fill the gap or mount the fitting on just one piece of the side, not two, which would mean making one hole bigger.