Jim DeLaney, Austintown, Ohio
When I did the undercutting on a 48" long coffee table top - using a raised panel bit - I did it on the router table.
I put a sawhorse to the front of the router table, then clamped a vertical piece of plywood to that to raise it to the height of the router table.
Then, resting the back edge of the tabletop on that, I made multiple passes, raising the bit each time, to get the undercut I wanted.
I felt that doing it that way was far safer - and easier, actually - than trying to do it free hand.