@ben_dw as far as the Pixel devices go, the Titan M chip in the Pixel 3 grants a lot of additional functionality in Graphene. I don’t know the specifics of what it’s currently used for but I’m told it’s a significant difference. The Pixel 2 has an off the shelf HSM which does similar things, but not everything the Titan M does. The Pixel 1 doesn’t have a dedicated HSM at all AFAIK, which is the main reason it’s a “Legacy” device according to Graphene.