Newtonian Equal and opposite force .. I've had a Shop colleague demonstrate the use of a beam sticking out from the wall
and after loosening the spokes in the effected area, slamming the inside of the wheel down over the beam,

to mechanically bend the flat spot outward .. then re tension the spokes

Mostly used on bike where the cost of another rim or wheel was over budget. And it was not a Fancy Bike ..

Kids Bikes primarily