I've searched for this answer for awhile and finally received a reply from Best Malz.
thank you for your friendly Email with the pleasing feedback to our BEST Red X®.
I would like to ask for your kind understanding that I am not allowed to reveal all the detailed secrets of this innovative craft malt. But you can be absolutely sure, that it is far more than a simple blend of 2-3 conventional malt types. We have developed this type during several months with our experts and by conducting also very intensive trials in partnership with several chummy brewers (using very different brewhouses, batch-sizes and technologies of brewing) to verify the results (of getting out excellent reddish beers with the utmost probability).
So the mentioned rumors are what they are: only rumors, maybe released by competitive maltsters in the market, who are not able to offer such products (and who may be a bit jealous about it?).
So thank you for your understanding and for using our products, don´t hesitate to ask for any further information.
All the BEST for your further brews and
Best regards
BESTMALZ AG