Cool white CFLs?

[BobBong]

i wondered if they would even be worth having in the flowering cab.

depending on the wattage of the HPS, it wouldn't be needed.. no. HPS is significantly higher lumen than any fluorescent light.
Now if you wanted to use the blue spectrum CFL's through out the whole veg with the HPS then remove the CFL's for flower with the 12/12 to increase the red:blue ratio..you could do that too..

your grow. you decide. HPS > CFL anyday.