Is there any chance we might see heresies in the game get some love in the not too distant future, such as some unique features appropriate for them as well as more flavor events and decisions? Currently in game they just seem to serve as only a minor inconvenience that really only turns into a major problem or watered down opportunity in certain situations. Otherwise they don't really offer much to play as one, as they're either a copy of the parent religion with nearly identical features, or they amputate a lot of features from the parent religion without offering much in its place.
Also on a side idea, could there be a means to introduce a system to create pagan heresies with the new holy fury Reformation system, maybe where, with certain conditions, an old Norse character who becomes powerful enough could declare a second Reformation in their own image and doctorines to oppose the original with the ability as a player to name that heresy, and otherwise have the names somewhat randomize to reflect on the new Reformation Heresy? It would probably be a good idea to limit the number of created heresies for each religion as well to maybe only 2 or 3 along with a time gap between each one to prevent exploitation and any wacky ai shenanigans. Maybe even force the heretic reformer to choose 2 or 3 different doctrines so that there isn't heresies that are just rebrandings of the original Reformation.
Just a random idea ¯\_(ツ)_/¯.
