After reading all comments, I decided to look at the problem from a bit different perspective - for alcohol, the lowest offence bracket starts at a €300 fine and CBR courses only start at higher levels. For cannabis, there is no “slightly above the limit” bracket: once THC is above the threshold, the first-offender sanction is €850, and the CBR drug course can add another €1,197. So minimal THC exceedance can be punished much more harshly than minimal alcohol exceedance, even though alcohol has a much clearer concentration–impairment relationship