If choosing to mitigate taxes is wrong, is it also wrong to choose not to donate additional money to the US treasury? It seems unlikely that the legal tax rate

If choosing to mitigate taxes is wrong, is it also wrong to choose not to donate additional money to the US treasury? It seems unlikely that the legal tax rate is the precise amount of money that you should owe society if you calculated it from first principles somehow. And so either mitigating taxes or donating additional taxes would be the 'moral' thing to do.