Paul, the “heresy” that was later declared of the Great Council of Moscow had to do with it’s dogmatization of Russian liturgical ritual at the expense of those of the EP. The error of the council had nothing to do with its teaching on icons. I suspect the “heresy” of the council was more jurisdictional nonsense between the Russian Church and the EP that has been going on for about 600 years. That being said, the Stoglav Councils teaching on icons stands as completely Orthodox.