Well, updated the Fichier data, on looking over the various sources etc, one of them is somebody's family tree, which appears very well researched although few sources are actually cited. This is the part that is relevant to your question:
A year after Rene's marriage to Anne, Fr. Jean de Quen wrote in the Jesuit Relations that he had conducted an abjuration of heresy in his chamber in the presence of Jean Jobin, Pierre du Val and Fr. Chastlaine, according to the formula of the Council of Trent with a boy called Rene Voie.
So if you have access to Jesuit relations you can verify it, but that appears to have been what it was about. A flirt with the religion due to his wife being originally of that faith.