I received this brand new led from TheOnlyDocc, who managed to get some samples from Osram. Partnr is KP CSLNM1 F1, brightness bin 7N (lowest bin on the datasheet), chromaticity bin A. Datasheet here: https://www.osram.com/media/resource/hires/osram-dam-2494973/KP%2520CSLNM1.F1.pdf
It is clearly the same generation as the White Flat, 1mm2 die, the die is a phosfor-converted blue led with a surprisingly uniform emission surface.
The spectrum at 50mA (does not change noticably at an angle or at higher currents):
Now that is efficient!, no CRI to match (it does have a CRI of 31 btw), so no light wasted for inefficient red colours, everything goes to where your eyes are most sensitive to. The appearance is a pale green, not as deep green as a single wavelength led, and when things are illuminated you can distuinguish colours faintly.
For completeness, here's the tint:
The performance (on a 16mm XP DTP board from Kaidomain) was a surprise, I plotted the data for comparison together with the 1mm2 White Flat.
For my method see my XP-L test from a few years ago, found via my sigline.
I think it is a good achievement but to be expected that the output is higher than the White Flat, but what is the real surprise is how it handles high currents: it maxes out at almost 7A, and at 9A where I stopped the test the output was hardly less. Mind that this is a 1mm2 led Also going back to lower currents showed almost the same performance as before the 9A abuse. That makes the expectation for the HX Boost even higher.
Should be fun to make a thrower at 4-5 amps with this one.
Thanks to The OnlyDocc for sending me two of these leds.
Edit: a first test of this led in a flashlight in post#29.