That's just like LHR where the "priority" lines take longer than the regular ones because the airports are terrible at scaling the number of priority lines as the load increases.
ARN does an "ok" job at that, they scale up and down depending on priority lane passengers. In CPH they made a separate priority area which can't be scaled, that is just bad by design. If you end up doing some halfassed 70% of the time it is better not to do it or not offer it at all. It is not a gesture, priority lanes are something that people account for in their travel scheduling.