Hi,
Do you mean the first OSC in the Analog modules?
You can fine tune the engine and fine tune the other two OSCs in a Analog module seperately.
It can be discussed, if a seperate fine tuning for OSC 1 in the Analog engines is needed. In some cases it can be prefered to detune two OSCs on each side of a center tuning, instead of just detuning one OSC to one side of the center tuning. But in some amount this can be done in a little more difficult way by using the Engine fine tune to tune OSC 1 and then fine tune the other OSCs according to that, keeping in mind that the Engines fine tune affect all OSCs in the Analog module.
Pigments also have the Drift parameter and the Unison modes.
It's quite normal, that a OSC 1 can't be fine tuned. But i would'nt mind having the possibility.
I guess Arturia have decided a fine tunig for OSC 1 in the Analog module is not needed. Why do you think it's important?