Avoid going straight from an exhausting full practice run into the real assessment. Being mentally fresh is more valuable than having the practice interface fresh in your memory.

A final practice can be useful, but it also consumes attention and decision-making energy. If the practice run is long or stressful, carrying that fatigue into the real assessment can outweigh the benefit.

You might review one or two short drills in the morning, stop, take a proper break, eat, and then begin the real assessment when you feel alert rather than completing a full simulation immediately beforehand.

Use the final practice session to confirm your process, not to test your stamina. Leave enough time to reset, check your computer setup, and start Solve when you can focus without rushing. If useful, this guide on McKinsey Solve guide gives more detail.

I would leave a break. Full mocks make me mentally cooked.

Short review then reset worked better for me.