Hi Paul.
(May be I did not understand your question.) I am sure there is a solution (we have implemented it in our products).
From my point of view there are several possibilities (e.g.:
1. task is completed -> request to the server to complete task
2. get next task -> request to the server (query for next user task) and as a response you can get next task form- depends on your form technology.
3. frontend can parse new user task form and display it.
)
Regards
Martin