As I said at the beginning, it's important not to make an exception for mental illness and mental disorders. In fact, mental disorders are already being considered as an important component driving the request. Assessors and health care providers already do this. I don't think there's a big lack of training among people already involved in this practice, since these are cases they see.
As for your comment about social acceptability, it's only if you say that everyone has to agree that the deadline will be too difficult to meet. If we say that consensus may not be the right objective to aim for, the deadline could become more realistic.