I mean, it's impossible to know, we have virtually no primary sources from that time apart from later Ottoman defters which themselves aren't entirely accurate and also can't really be used as proper census material due to their methodology and primary purpose (military).

The number of surviving Bosnian church documents - either primary or secondary - is in double digits, and probably as low as 20. Any estimates made about the size of different religious populations in medieval Bosnia are going to be very vague guesses. And yes, while contemporary works on the Bosnian Church by authors such as Noel Malcolm and John Fine reject the dualist character of the church, I do not believe you can claim it has been 'thoroughly debunked' if we consider works by other authors like Solovjev who does make certain convincing arguments.