I have seen a few posts about people who need to leave their pool unattended for an extended period of time (7-10 days). And the use of pucks is often a suggestion. Why couldn't the FC level be raised based on average daily loss? So if you will be leaving for 10 days and your average loss is 2 ppm, you increase your FC level above where you want it by 20ppm.
Does the FC diminish faster when at higher levels due to evaporation? If not, why would this not be a good solution?