Peters goes for Bellarmine’s view over that of Suarez and Cajetan: “Through heresy notoriously and openly expressed, the Roman Pontiff, should he fall into such, is, by that very fact, and before any declaratory sentence of the Church, deprived of his power of jurisdiction.” However, it seems to me, there is effectively no practical difference as to be heresy the error has to be obstinate and and so the admonition of the Pope’s proper counsellors has the same effect as the declaratory sentence by the same. Peters doesn’t reach this point because he eschews “detailed canonical examination of the mechanics for assessing possible papal heresy”.