Will Buxton mentioned on F1TV how Mercedes is "scrubbing" race tires by running them for one lap right now to prep them for the race. Any idea how that helps? I missed that part.
A fresh shiny tyre is usually faster over 2 -3 laps but the behaviour after that will be less stable because for that fast qualifying lap you're trying to just stay overheating it. By scrubbing it is put through a heat cycle under relatively controlled circumstances you're basically making it a dependable tyre that will feel better faster to start putting in consecutive race laps.