Return to saved velocity?

I'm afraid I don't follow. You say after you reset the velocity curve, the flat curve survived preset changes? Sounds to me like it's working as designed.

Ian, I think this is exactly how it is supposed to work, with all the parameters.

When you select a preset, this preset potentially includes values for all parameters Pianoteq knows. But when you 'freeze' a parameter, you tell Pianoteq that upon loading a preset, the currently selected value should not be overwritten.

For example, I have frozen the main volume, the equaliser and all the velocity curves. When I set the volume to e.g. -10dB and I store a preset, then this preset includes the -10dB volume setting: fair enough. When I load this preset and the main volume is not frozen, -10dB are restored regardless of what was set at that moment. When I freeze the volume, Pianoteq does not touch it anymore upon loading a parameter-- at all. So if I set it to-35dB and select my preset with the stored -10, the volume will remain at -35dB.

In the case of the velocity curve the behaviour is essentially the same. The preset contains a certain curve, and Pianoteq's current state also contains a certain curve. The two can be the same, but generally won't. Upon selecting a preset, only one of two things can happen: (1) the current velocity curve is replaced by the curve in the preset, or (2) the current velocity curve is kept (i.e., the velocity curve is frozen).

Certain parameters have their own preset manager, so you can save mini-presets just for a certain parameter or parameter set. The velocity curves are one example (one should only note that note-on, note-off and pedal velocity curves are treated as one group); the equaliser is another, as are the effects. But they will still be stored in a 'complete' preset, and the same behaviour happens when you freeze them.

Edit:

Trying to word it differently: Freezing applies to the parameters currently in the GUI, NOT to those in the saved presets. If you modify a velocity curve after loading a preset, and want this curve kept for other presets, the best way is to save it in a named mini-preset and load it separately (by clicking on its name) when you need it.