Hmmm, don't know if I'd word it that way, if I am understanding you correctly. I'd say it is definitely a good idea to ensure that your carbon cannot be sucked into pumps (this is how it has caused HLLE in several PA incidents) nor fluidized, no matter what length of time you run it. Lots of beneficial husbandry routines have potential risks--you can overdose kalkwasser, vodka, use too much GFO, etc. As long as we are aware of the risks and take appropriate steps to prevent any problems there's no reason to stop using them. 5 beers in, just a caveat. I'm amazed I'm still spelling okay!