As you rightly state Muslims cannot be fully submitted to Islam until we fully accept without finding any resistance within ourselves to the ahkaam of the Shariah no matter how incomprehensible they might seem. Allah Ta'ala states, 4:65 But no, by the Lord, they can have no (real) Faith, until they make thee judge in all disputes between them, and find in their souls no resistance against Thy decisions, but accept them with the fullest conviction. May Allah Ta'ala guide us all and open up our hearts fully to His guidance.