after having slept and reread what I wrote, I feel like I should edit my below 5 hp priority because i did make a mistake.
below 5 hp it is acceptable to burn a proc, in the same priorty as the 5 HP list, but only when the builders are off GCD and wont be coming up withing .2 seconds, it just happens very rarely. not sure why i was so dramatic about not burning them, just ment to emphasize that you shouldnt be burning the procs as soon as they show up.
feel free for someone to correct me here, but I believe the value of CS is not in its ability to deal damage, but generate HoPo. there will be situations which you will sit in where you will have unused hopo generators and at 5 holy power, there is absolutely zero reason to cast CS.
now I might be misunderstanding what you mean due to the above correction I had to make, if everything is on cd anyway, yes you should burn a proc and not bank it.