The ticket has been logged recently in our issue management system and we are afraid that it is pending for analysis. We will surely investigate it on first come first serve basis according to the policy of free support model.
Furthermore, please note that it is quite complex requirements. Existing functionality of flattening the PDF form remove the form fields and place the values at their location. So, in the output PDF, there is form. Detailed investigation need to be done in order to determine whether it is feasible to unflatten a form field after flattening it. We will surely inform you once we have further updates in this regard.
We apologize for the inconvenience.