The amount of swaging on the throttle plate screws on the Walbro carbs seems to vary quite a bit from carb to carb. Some easily tolerate removal and reuse of all parts where others have the screw thread end swaged so much that it will indeed destroy the shaft when removed. You just have to use good judgement whether the parts are OK for reuse. I have also seen guys push so hard on their screwdriver that they bend the shaft where the screw goes through and any bending will fracture the shaft making it prone to failure at a later date. Again, a component inspection and good judgement is in order to determine whether the parts are reusable. A blanket statement that parts are not reusable is just not in order here.