tl;dr – skilled, supported, concentrated exploration
There are no sessions or formal session-end debriefs, but the team will want to stop and sit back from time to time and come to some conclusions about what they’ve found. The person (or people) on point are switched around regularly – scouting is fatiguing, and diversity is important. People with different specialities are used as required, and The Scout need not be a tester.
Exploration often has a sense of a frontier, a boundary between the known and unknown. The frontier is fundamental to exploration, and The Scout pushes it ever onwards. We understand, of course, that testing has really wiggly and sometimes discontiguous boundaries, and that the territory behind the boundary may not be well-known, and is likely to change unexpectedly. The team will understand this boundary better than anyone else, and will need to come to an understanding about how much they need to be able to notate and share information about the frontier.
This approach is all about discovery. It’s not cheap, nor is it exhaustive, but it is valuable. The project gambles time in return for information, so The Scout needs to know what the project is interested in. I expect there would be tussles about what The Scout would be exploring, and what they would be looking for. So much the better.
Note: This an idea. I’ve not worked (quite) like this. Maybe, though, this idea triggers something that you would like to try with your team. Let me know how you get on.
* or one group, but I’ll write in the singular to keep the grammar simple