Under the hoodTier: how much it should matter to you
3Useful: my rating, 1 to 5
3Signal: worth watching, 1 to 5
Session StateArea: what it touches
Internal ChangesKind: in v2.1.242,
Internal ChangesSection of the release
What
Cost totals (input tokens, lines removed, cache-creation tokens, web-search requests), the last API completion timestamp, the package-manager version cache and the one-shot "fast icon hint shown" flag are no longer shared across the whole process; each is now scoped to a host, so separate sessions no longer share them.
Evidence
fastIconHintShown
Strings lifted out of the shipped bundle, so the claim above can be checked against them.