I don't know who designed that tool but they must LOVE us
My Autokraft MkIV came with a steel version of said tool. Tried it. POS.
Some Liquid Wrench and a few minutes and it finally gave with the old lead hammer.
And I agree with Bob. Most guys beat the hell out of those things. The nut doesn't take the torque, just keeps the wheel 'on'. Give nice firm whacks and use your ears. They'll tell you when you're done.
rodneym