I did the design in the attached Sample3.uds file. In the Design Results, it reports an Actual Estimated Drain Voltage of 666.69 volts.
I then changed VOR, in the Key Parameters tab, from the default value of 108.7 volts to 100 volts, and saved this as Sample4.uds. I would expect the VDRAIN Estimated value to go down accordingly. However, the Design Results still reports 666.69 volts!