Would it be possible in some way to link an activity to an errand and have the notes from the activity added as a message in the errand?
Probably some different ways of accomplishing this, it is possible to add a extra field (type=Appointment) to Request. This will allow you to connect a request to a appointment in CRM. To fetch data from connected appointment, I simply created a Trigger script on "Saving a request":
Thanks! Will present this to the customer.