CFPDFForm currently throws an application exception when processing LCD PDFs that have been signed and submitted, using the default 'Sign Data and Submit Settings' in LCD.
Now this has been fixed... And now data can be extracted from a signed PDFForm.
In signed pdf extra node named <signatures> was introduced in <xfa:data> element. Earlier assumption was that <xfa:data> will contain only forms data. Now signatures will be ignored before constructing form data DOM.