Acceleration boost upgrade showing in my app tonight in the UK (M3 LR AWD).
The "stealth" performance models are different to AWD+boost - they get a different rear motor to the AWD (980 vs 990 - with a more capable inverter I believe) and they get track modes. I haven't seen anyone saying they managed to get hold of a new one recently but you could try ringing tesla.
The LR AWD+boost sits between the LR AWD and the P in terms of 0-60 (roughly 4s, 3.5s and 3s on a fair comparison) but does not get the track mode stuff if that matters to you. Of course the full P gets upgraded brakes, slightly lowered suspension, rear spoiler, higher top speed etc.