Can service Resources use chatter to communicate in the feed of an appointment record?

Are there special permission sets that can be used if the field service is delegated to contract workers?

Can Knowledge articles be attached to Work Type records? For example, a Document where it explains the technical procedure to be implemented?

Which one is NOT one of the benefits which can be gotten via the Schedule Automation?

If you wanted an optimized scheduled day within a territory after a sudden change (eg. one of the workers is sick and can't work). Which Schedule Optimization would you use?