I see the assumption of SSO/MFA as
defeating the SSO tax: If we assume SSO/MFA, there is no base price vs premium tier price distinction wrt SSO -- all customers get it. For free auth modes (SSO, but probably not MFA due to SMS costs?), esp. b2b, it's easy to extend into free not-a-customer tiers. As SSO in turn eliminates account sharing, everyone wins: all users get more security, and providers see less account abuse/sharing (and hacks). And hopefully, there's something more valuable & enterprise-aligned to charge for wrt security than everyone-grade-SSO, e.g., audit logs, AD, & training.
RE:Output, I like that view -
* Passive (data ingest, ...): bad; and data gravity & analytics value + dropping storage prices means you want to encourage collection vs discourage (up to data liability hazards)
* Active usage based, esp. user-visible: You're using CPU/GPU hours to run something. Except agreed, the further you are from a dev, the more annoyed they are. An active user can be a proxy for this ("Editor", "Viewer", "Creator", ...), but users make it hard to get more scalable pricing, e.g., 1 power user should be able to get insane value, and be charged proportionally.
* Output: If the result of a task is an artifact, like a project/model/etc., it's a proxy for unit of value achieved. In a sense, Slack's "Free tier conversion to get search history of recent chats" comes from recognizing this.
I find it interesting companies like Figma are by User, not Project...