There comes a time when even the sharpest tool in the box will get mentally maxed out while dealing with the complexities of the tasks required. Personally, I am not confident that the training and testing systems currently in use, do not test adequately through the point of highest workload and on into the area of overload. How well an individual prioritises tasks and makes conscious or unconscious decisions about what to "drop" in order to focus on the most critical elements, while in overload, needs to be more effective.
Of course, this could result in a decision as to that individuals suitability for the role. Pilots are not super-human. The complexity of automation should at least reasonably align with the capability of a candidate for testing. Pushing the limits is a recipe for disaster.
Just my opinion without prejudice, having been to the edge when it turned out to be a not very fun day.
IG
Oh I passed with Uplinker but in principle, I agree