To me, foxtails are just added, sometimes bonus, sepals with trichomes just as potent as the main buds. Foxtailing could be the plant seeking to rapidly express essential oils, THC, etc. but it is restricted by the current buds (already maxed out, getting old) and quickly adds on more biomass, more sepals/trichomes.
So if the pot is for yourself (not to be sold), foxtails are not a problem other than indicating some stress (e.g., light, N, heat) recently, perhaps ongoing, with any stress presumably resulting in some loss of potential quality and/or yield.
So if the pot is for yourself (not to be sold), foxtails are not a problem other than indicating some stress (e.g., light, N, heat) recently, perhaps ongoing, with any stress presumably resulting in some loss of potential quality and/or yield.