Data Persistence in workflows triggered through interactive forms.

I have read through all the threads regarding Data persistence and do understand that form data is stored in xml format. I still have the following doubt:

For all the custom workflows we are developing for this client (using Adobe interactive forms as the UI in the workflows) we want to have local data persistence. Is there a model which covers data collected through the forms, including those data that are retrieved from SAP at the beginning of the workflow, and those data that are manually entered by the forms user?

Scenario : <b>cost xx - approver 1

cost xx + 1 - approver 2

Form data filled, cost xx and hence a email goes to approver 1.

Now, details changes and cost for that sales order increases to xx + 1.</b>

Will my email still be in the inbox of approver 1?

What if I want data persistence where from the initiation to the end of workflow the data should be persisted irrespective of the changes.

Thanks,

Kavitha