If you have fluctuating line voltage it is "supposed" to prevent the voltage drop from hitting the lamp.
So your enlarging lamp won't go dim on you in the middle of an exposure.
I have not actually put a meter on the input and output of a stabilizer to see just how much it will stabilize the voltage to the head.

Different stabilizers use different techniques to stabilize the voltage.
I don't know the design behind the one for the Chromega-D.
The stabilizer for the C760 used an 85v output, so it cut the voltage to the bulb down from 110v to 85v. So the line voltage could sag down to about 90v w/o affecting the bulb. What the 85v output voltage did to the color temp of the bulb is a different matter.

If the light bulb in your home dims once in a while, that is an indication of a small voltage drop.
I see that when my wife turns on the electric clothes dryer.