We have increased the capacity of the scratch storage from ~350TB to ~522TB this week, matching the capacity of the old server (Panasas) that was decommissioned back in April. The additional drives were installed without any downtime, with no impact on jobs.
This also means larger number of drives contributing to parallel reads and writes, potentially increasing the overall performance of the filesystem.
No user action needed, and you should not see any differences in the way you are using the scratch space.