I agree with Lane's remarks in general. Confessions have both a polemical and pedagogical function (see my series,
"On the Validity & Value of Confessions of Faith"). I still contend, however, that the 17th century confessions do not speak to every issue. So one will need to say more than what's said in the WCF in order to present the whole counsel of God. Moreover, we should be modest and concede the high probability that the doctrinal formulae in these confessions are not 100% accurate all the time. Otherwise, we're not too far from Rome's claims, which the Reformers and Puritans earnestly opposed.