Maybe it'd work to just timebox the task, i.e. 'work on one bug for an hour', along with 'document everything you find and learn' (and add it to the public issu

Maybe it'd work to just timebox the task, i.e. 'work on one bug for an hour', along with 'document everything you find and learn' (and add it to the public issue). I'm a habitual documenter and I could imagine something like those 'papertrails' being a useful way to evaluate someone's thought processes (and written communication skills).