Wheel Adapter Help !!

The instructions included with adapters plainly state Not for racing or performance use" something like that. Also states "Make sure the part seats flat against the drum or hub." People ignored those warnings and adapters got a bad reputation.
I just installed 4 a few days ago. There were weighs welded to the drums (factory balancing) which interfeared with proper seating on 2 drums. Very minimal grinding to those weighs solved the problem.
I know my adapters are properly installed (right and tight). No worries here.