Re flicker: I have seen flicker when the shutter speed is set high (say, 1/500) but it vanishes when I reduce if to 1/60 or so.
As for the auto-sensing: it's the darnedest thing, I thought it was pulling from my favorites, but it might have been illusory.
Then I started thinking with my engineer's hat: how *could* they do this? And realized that since the camera has a gyro and a list of lenses and an always-on image processor, you could calibrate image changes with known rotations in real time, detecting field of view and mapping that back to the closest available pre-chosen lens. It *could* be possible... but if it were being done, I'd think they'd be trumpeting it, considering it does little to sell *new* lenses.