HighlandReefer
Team RC
Usually there are some contaminates in just about every product. The MSDS sheet does not disclose these contaminates. Whether not not these contaminates will precipitate out during the restoring process, I don't know. 
Is it possible the NaOH soak had a greater impact on the granular GFO, and actually broke some of the chemical bonds that hold the PhosBan grains together causing the deterioration and the strong colored liquids?
Yes. The solubility of iron actually increases as pH rises above pH 8 or so due to the formation of Fe(OH)4- .
I am not sure what is holding the particles together in a granular form, but if you dissolve away the iron that is bridging between tiny particles, they may be released into solution.
So, would pellet form of GFO be more resilient to the regeneration process?
To make a ~0.1 M NaOH solution, dissolve ~4g NaOH in 1L of water.