Update the associations of a task in a sequence

When applying a sequence with tasks in a deal, the association of this task is not created for the deal. However our contacts have sometimes 500+ deals, and therefore the link to a specific deals is absolutely necessary.

I’ve seen variations of this idea, but this one perfectly describes what I need. I work Deals, not Contacts. We need to be able to enroll a Deal in a Sequence, and have those activities log to the appropriate Deal.