Not quite unobtainium. I have one; I bought it in July 2020 when BMW still had all pictures embargoed and took delivery in November (see my post at
2021 S1000XR M Package Announced & Bought!). The adaptive headlight question in this thread was from before I took delivery. Your post reminded me that, despite 3100 miles, I never performed a night ride test to see if/how well the adaptive headlight works. Thanks to a 69 F Western North Carolina day, I just got back from doing that test.
The adaptive headlight works and it's awesome. There are eight lights in a headlight assembly that has both daytime running lights and adaptive headlights (see pic). The two bottom/outside lights are the daytime running lights (lit in the pic below). Above those are four main headlights, two on each side (all dark in this pic because these lights are off when the daytime running lights are on). The two main headlights on the bike's right side comprise the low beam; they throw a inverted trapezoid with the small top at the bike and the large base lighting the road at low beam height/distance. The two main headlights on the bike's left side comprise the high beam; they throw a very bright long range rectangle above the center half of the low beam trapezoid. The two lights at the top of the headlight assembly are the adaptive headlights, one on each side; they have slash lines separating different focusing zones in the pic below. When the bike is leaned, the adaptive headlight on the inside of the curve fills in the area that's above the low beam trapezoid and on the inside side of the high beam rectangle. This lights up the area that the low beam cannot reach because it's too low when leaned over. The strength of each adaptive headlight is roughly the same as the low beam. The adaptive headlights work during both low beam and high beam. It's a little disconcerting to get used to; they pop on when you hit a set lean angle. They leave me wishing they would come on just before I start the lean, i.e., follow the road before the lean starts, but that would require road tracking sensors. That said, they definitely light the blind spot caused by the lean.