In this post Ben wrote the following:
Stabilizer has little or no effect on bromine, so as long as some bromide (from past bromine use) remains in the pool, you will have an UNstabilized bromine pool . . . even though you are adding chlorine.
While it is true that there is no evidence that bromine combines with CYA the way that chlorine does so does not get any direct sunlight protection through reduction in hypobromous acid levels, that does not mean that there is no protection from degradation from sunlight at all from CYA. CYA appears to protect chlorine through two different mechanisms -- not only from combining with chlorine, but also through a direct shielding effect where CYA absorbs UV from sunlight protecting lower depths of the water. It is this effect that probably explains what is seen when one gets to higher 80 ppm CYA levels where the rate of chlorine loss is lower even when the FC/CYA ratio is kept the same meaning that the amount of hypochlorous acid is the same.

So it is possible that this same CYA shielding effect would help protect bromine as well -- the main question is how much. Since CYA doesn't make the bromine ineffective, one could raise the CYA to 100 ppm and see if the amount of added chlorine needed to sustain a constant bromine level is reduced in a pool exposed to sunlight. Lower CYA levels such as 30 ppm would not be expected to have a noticeable effect.

Richard