Sorry for the delay in replying – I had to research.

You are correct that the default tuning of the Diatonic shifter on Eclipse is for the common A-440.

This can be changed in the PARAMETER area:

Press PARAMETER <EDIT FXA> or <EDIT FXB> depending on which effects block holds the program.

Select the MASTERS softkey.

Hit PARAMETER key once, then the CAL softkey.

The "TUNE" parameter will be selected – this is the one you want. It sets the tuning in cents either side of A-440.

For 430Hz you want -40 cents. Don't forget to save the preset afterwards.