The OVP and VR_RDY pins are only logic level outputs to indicate the status of the voltage regulator, and shouldn't have any effect on the OVP threshold. The OVP threshold is derived by comparing VDIFF (effectively the output voltage of the regulator) and the reference VID value from a DAC + 175mV.

You might be able to tweek the reference voltage from the DAC by pulling the DAC pin up to a higher voltage (depending on the output impedance of the DAC), although doing this might damage the voltage regulator. If that doesn't work, the only other way to overcome OVP is to change the VID values.