Please remember that driver and driver count do not determine how an iem will sound completely. While a good set of drivers and multiple drivers may lead to good sound, it's not the complete story. How the driver(s) are tuned will determine how good the iems are. A great example is Campfire Audio. If I'm not mistaken, I believe they still use Bellsing BAs, and even then, many people will say that CFA has a unique and great sound regardless of not being Knowles BAs. Another example would the Custom Art Fibae Blacks. They use one Knowless driver and even then, in a blind audio testing, people thought that there were multiple drivers being used.
I guess my point is, while Knowles does have a solid reputation of producing good BAs, that is not the complete story as tuning can make an iem sound moles better, or possible even ruin an iems sound.