Hlg claims those numbers are fudged but hey theyre the competition. But personally i wouldnt believe the numbers. But the w per diode approach is very good. 4 v1 qbs would run around .1-.15w per diode for that space, about twice as soft as a sf fixture. Around 2.8 ppf/w according to hlg. Almost 1200 diodes.
Im not sure if youre actually refering to the qbs but they arent blurple and actually a very good alternative for US peeps:
Youd have the same amount of white diodes, lm561c, for 120$ plus driver cost (30-40$). Iirc hlg shipps for free, no china shipping.