My body naturally tells me when I'm not thirsty anymore. I'm not sure my body would tell me when I'm reaching toxic levels of glycyrrhizic acid if I'm snacking on licorice all day.
Just a label like "Licorice contains glycyrrhizic acid. Do not consume more than 10 mg glycyrrhizic acid per day."
Or even just "Licorice contains glycyrrhizic acid." would be enough for people to google it.
People have died from drinking too much water, probably more than have been killed by liquorice.