probably has to do with excess volume of air? ... are these like grove bags or something? Can you close them up with less air trapped inside so that it's more similar to what you'd have if 3-12 oz was in there? however it conrols RH, it'll still follow the same rules.
i'd also take their 10-day timeline as a grain of salt... density of buds, resulting rh, and temperature will likely create some variance. Proper temp and rh in a mesh rack takes 10-14 days.