Stacking color conversion and polarizing filters?

Well, they do, kind of...

80A filter converts 3200K to 5500K, requires 2 stops exposure increase, results in more "blue" light hitting the sensor once all is said and done.

It increases the amount of desired section of light spectrum collection, and provides sensor with actual light data as opposed to correcting the WB in post processing that results in an increase in chroma noise because of insufficient actual light data.
80A can be very useful in digital photography.
Best Regards,
Renato

'The world is going to pieces and people like Adams and Weston are photographing rocks.' Henri Cartier Bresson, in the 1930's