@DavidR,
Very good for these forums that was how it was presented in the other thread, always give two sides of a story, so the reader can make up his own mind.
It was as the very link that you posted has previously been posted so we have seen their rebuttal, the 3rd party bitdefender engine is disabled by default because they feel it may be too much for older/user systems. But it is fine to enable it in a test version.
When AV Comparatives gave their write up, it mentioned that there were substantial differences between the two versions. To me that sounds much more than the 3rd party engine just being disabled in the user available version.