It's modular by design, but the UI is the primary interface — no standalone CLI yet.
On the opinionated/piecemeal question: the data layer is intentionally unopinionated. Everything is plain JSON files — tasks.json, inbox.json, decisions.json, etc. Any tool that can read/write local files can participate. I've had Claude Code, Cursor, and custom scripts all interacting with the same task queue without touching the web UI. So at the data level, it's fully piecemeal.
The UI is more opinionated — it assumes an Eisenhower matrix + kanban + inbox workflow. But you don't have to use all of it. Some people just use the kanban and ignore the priority matrix entirely.
A CLI is an interesting idea and something I've thought about. The API is already there (token-optimized REST endpoints for everything), so wrapping it in a mc tasks list --assignedTo=developer --kanban=in-progress style CLI would be straightforward. If that's something you'd use, I'd bump it up the roadmap — would you open an issue?
Haven't looked at beads specifically — could you share more about what you mean by tracking state with beads? Curious if it maps to something Mission Control already does (the checkpoint/snapshot system saves full workspace state and lets you roll back) or if it's a different paradigm entirely.