I was referring to the testing of various new cooling architecture components for the 2021 season, which was reported on by multiple sources, including @SomersF1. Believe the testing began at Sakhir and carried on through the post-season test:
"Meanwhile, it’s believed the team also installed the experimental radiator layout that was briefly tested on Valtteri Bottas’ car at the Sakhir GP, owing to the same rear bodywork and cooling outlet being selected as was used in that test. It’s understood that this new layout was designed to work in conjunction with next year's power unit . . .
. . . Therefore, to maintain reliability, the team was likely forced to run in a lower power setting than would ordinarily be the case. This was perhaps underlined by the Mercedes pair being the slowest in the top speed trap during the race."
https://us.motorsport.com/f1/news/merce ... t/4930907/
