- ways that Buddhism and other traditions have been syncretised or co-practised to date without harmful effects
The Jingjiao (luminous religion) and the Jesus Sutras is pretty interesting and still going today. But Buddhism has blended in many ways right? They even had greco-buddhism and all kinds of cultural amalgamations. Today we can see it blending into Western culture in various ways. But to me the important point becomes whether schools are dealing with an entire body of teachings or a fragmented curriculum. If you only have a piece of the entire body of teachings then certainly there will be problems.
On the surface (conventional level) I think blending can be problematic. I've always been interested in other schools and have found many legitimate parallels but I've been Buddhist all my life, in the same tradition and lineage amd am very greatful for that.