It appears the consensus is that a drum sander would be the right tool and that a hand plane would also work, but there is no clear consensus about what would happen on the planer, and no one reported having tried it.
At the same time, there was no suggestion that light passes would be dangerous or would damage the planer like trying to run an end grain cutting board through it.
In light of the altruistic nature of the FOG forum (and lack of ready access to a drum sander), I feel compelled to try it and report the results. If it explodes, at least we will have a little more information for future use and I won't be set back that much.
Will try this tomorrow and report back, hopefully with a video from both sides.