The “B” pots are a linear taper. Adding a resistor across lugs 1 and 3 is adding a linear resistance to a linear taper. Therefore, the resulting taper is unchanged. Only the resistance value changes to @25K.
If you have a log pot; either “A” taper, “C” taper or some other, adding a linear resistance in the form of a resistor will definitely change the taper by reducing the slope of the log curve.
I’m not sure about the result of adding 2 25K resistors as mentioned. I would like to try that and plot a resistance curve as the wiper is rotated through the 300 degree (or so) rotation.