My small, light, metal door opens/closes fine by hand, but binds when
the opener closes it. The top panel of the door has just enough
deflection to cause the mechanism to bind.

Perhaps trying to manually open/close the door while only touching the
door where the opener touches the door will reveal some binding that
does not occur when force is put on the door in a different place.

In networking, this is the "be the packet" approach, so here I guess
its the "be the opener" approach.

Dave