Watching the CAAs across Europe mark all the ATPL theory exams with 20% 'open questions' or essay questions would be hilarious.
There is a proposal on the table to introduce some questions that are not multi-choice, Paco tells me these are only those with numerical value answers. I understand that the German LBA have similar questions at the moment. If accepted by EASA I would not expect to see them before late 2018/2019.