I didn't get to tackle this over the weekend with holidays etc, and because one of the headlights popped off its adjuster servo. In case anyone else runs into this problem here's what I'm talking about. Sorry for the blurriness, it's dark in there and I couldn't focus on the right spot with the flash on.
Looking in from the bulb access panel towards the middle of the car you can see the round servo and its yellow plastic arm with a ball shape on the end. That ball end should be snug inside an attachment point on the bulb holder adaptive assembly. Perhaps while being shipped, the bulb assembly came off that ball, and was left flopping around somewhat - or at least with one degree of freedom that it shouldn't have.
I searched and came across similar stories on E90 and E82 forums, and of course they have it easier because the servo is much more accessible. With the F3x housing there is zero access aside from the bulb panel, and it's not possible to reach in and grab the assembly near this point of clip-in for the servo to pull it into place. Pulling from the back does not seem safe, there's too much flex.
In order to reach the clip point, I bent a metal skewer to give it a small L-shape at the end, which I could reach in and hook around the back of the assembly. I then warmed up the inside of the housing (blow dryer or heat gun would do) to soften the plastics, lubricated the clip and ball as best I could with a cotton swab, and got the skewer hook in a good spot. Thankfully, one firm pull popped it in.
Apparently this has happened to a few people after sever potholes or bumps. Hopefully it doesn't happen again, but I'm glad it's possible to DIY fix because these housings are very expensive.
Now I just need to get around to the retrofit...