SRSv2 4.0.31.0 is comprised of quality and reliability fixes. Release notes have been updated on docs.microsoft.com here.
November 1st Note: There has been an issue reported with script and 4.0.31.0 msi package compatibility. We reverted to 4.0.27.0 when creating an image with the CreateSRSMedia script while we work on resolving the issue. Devices with 4.0.27.0 will automatically update to 4.0.31.0 via the Store while we work on this issue.
