I realize I am a picky little sucker but am I over the line on this or am I wrong in the way I see this?
From the http://www.garymkatz.com/trimtechniques/hiddenpivotbookcaseinstall.htm
Edgebanding plywood shelving
I’ve done a lot of edgebanding and always hated the hair-line crack that develops between the plywood and the solid stock. That gap is caused by the inner plywood endgrain_ swelling from the glue, which puts a little belly in the edge and forces the banding away from top and bottom of the plywood. To prevent edge swelling problems, I used a Collins Ply-Prep bit and ‘routed’ a slightly concave nose on each shelf, (www.collinstool.com: $20.00)
End grain doesn’t swell, edge grain will!
I like the idea behind this bit, just think the explanation is off.
-- Folly ever comes cloaked in opportunity!