can we assemble XFA and Flatten pdfs?

Hi,

I am not sure if assembler can create a XFA + Flatten pdf to a XFA form.

I want to assemble a pdf1 (xfa)  with pdf2 (flatten) to produce a pdf3.

Pdf3 should not be completely xfa or flatten, so that i can submit pdf3 on hit of button and extract out xml out of it.

PDF1 is an application form

PDF2 is just instruction page, so i want to keep it as flatten to reduce size of this pdf.

PD3 should be XFA cum flatten, so when it is rendered to user and user clicks on submit button. It will submit the entire pdf.

Please let me know how do i do using assembler.

Regards

Sunil