I agree, I kind of circled the wrong part in blue. When I have done them I have always hammered on the hub behind the flange. The area behind my blue circle.Hammering the flange is not the way to go IMO
Once the flange is deformed, cone washers don't seat properly, flange doesn't matter with the hub properly, clamping force on the studs/flange is unpredictable, studs are tweaked.
Next time around, you have to wail on it harder, and so there cycle continues.
I've had able flanges that had to be filled flat on the hub matting face, and cone washer holes dressed up carefully with a countersink bit too remove a big burr caused from being beaten.
New hardware for the hubs is cheap. With while replacing it on a new to you truck if the existing stuff is not tip top