Sorry I misunderstood you, coli.
You had said "the driver is available but seems to be mainly used by audio integrators", and I thought you were saying that JBL's Beryllium driver could be purchased and used by another manufacturer.
You said that besides JBL, "Nobody else seems to sell speakers with those kind of compression drivers. Such a shame..."
I know of at least two US companies that build and sell speakers with Beryllium compression drivers. One is Classic Audio (formerly Classic Audio Reproductions), they've been doing so for many years, before Radian started selling their Beryllium drivers. Mine is the other company, and I've been offering Beryllium diaphragm compression drivers as an option for about a year now.