Activity Stream from a reference field

[Ace009]

OOTB, Is it possible for a record to have an activity stream that is based on a reference field? For example, Incident and Incident Tasks (has a field that references Incident).

The scenario:

This is on the backend/platform side, not Portal

I have a workflow that auto generates tasks, up to say 10 different tasks in order (the next task is generated when a task is Closed).  Suppose at task 3, the person completing that task would like to make a note that will be useful/needed for Task 5 or Task 7. Ideally, the folks handling the ticket do not need to head over to the Parent Incident for any information.  The folks assigned to these tasks gets emails and I would like for them to have all the information needed in that task alone.

Since the work notes for Incident Tasks are only for each individual task, it wouldn't fit the requirement. Mentioning someone could be a workaround since OOTB an email is generated but that's relying on someone digging into their Inbox. If the parent Incident's work notes could be used in the activity stream of the child Incident Tasks, then we'd have an Activity Stream that contains all work notes across all tasks.

Possible alternative solutions that could work:

- Create a text field on the Incident level and add it to the Incident Task form view. Then we'd have a text box that will be inherited by all Incident Tasks. Wont have the functionality of an Activity Stream, pure text. 

- Another approach would be to allow a user to input what note they want to add and to which Incident Task(s), store it into a workflow scratch pad variable (by modifying the workflow context), and use that scratchpad variable to append it to the Description of the desired task.  

Thoughts?