90% of the running-in time is around 100h after which there is a slow and progressive softening of the tone400 hours? Wow
The Sparkos recommendation on the volume stage of the Burson is also something I noticed that the Youtube reviewer Passion For Sound also preferred.
Sparkos are one of the actions you can do to fine tuning the system.
Burson invites you to experiment. The results depend on the whole system, as I wrote, with the Audeze LCD-2 I prefer the VIVIDs, this way is more sparkling.