My take on this is that, from a SW development POV, user stories are not the right unit of work. Instead, I treat user stories as "Epics". Stake holders can track that Epic for progress, as the unit of work from their POV.

Internally, the team splits Epics into "Spikes" (figure out what to do) and "Tasks" (executing on the things we need to do).

- Spikes are scoped to up to 3 days and their outcome is usually a doc and either a follow-up Spike or Tasks to execute.

- Tasks must be as small and unambiguous as possible (within reason).