Very good question

Who knows the signal pattern of the stock coil on the F75 in both the discrimination and all metal modes?
What I mean, maybe a picture of how the signal leaves and returns to the DD coil on the F75.
If you increase the sensitivity does this increase the detection pattern wider, deeper etc.

The electromagnetic footprint of the coil is exactly the same...... no matter what mode the detector is in....... the moment the unit is turned on. Increasing Sensitivity or lowering Disc only concerns how the electronics handles/processes what the coil 'sees'.