Update:
This was bugging me this morning, when I spilled probably at least a pint of gas while filling up, so I took it to task today.
I removed the filler neck cover under the fuel hatch - removing the 4 big screws and undoing the release latch nut to do so. With the cover removed, you can see to the right of the filler neck the smaller (about 1/2" OD" metal vent tube. I felt inside the filler to find the hole - it is angled back down the filler neck, a bad angle to blow into.
Using some 1/4" vacuum hose taped to a wire hanger and bent backward, I was able to fish the hose through the filler opening (holding the flap open with a scribe) and back up into the vent tube opening. This was a chore and took about 10 minutes to successfully get it seated in the vent tube. Then I blew 90 lbs of compressed air through the vacuum hose into the vent tube. I could hear the air rushing down into the tank and gurgling in the tank, so if it was clogged before it is not now. I'll report back after my next fillup to see if this was the issue. If this does not cure it, I'll pull the cover at the tank (under the second row seats) and blow out the line from there.