How to extract all Adobe fields quickly?

Dear Aspose support,

I need some help in processing a specific PDF document. My goal is to get every Adobe field in this document and its position + coordinates. Then, remove them from the document by flattening the document. What is the quickest way to do this? The attached document takes more than 60 seconds. I want it to take less time. Can you please review my algorithm below and suggest a faster alternative approach?

//Step 1: Get all Adobe fields.
Aspose.Pdf.Facades.Form form = new Aspose.Pdf.Facades.Form(filename);
Aspose.Pdf.Facades.FormFieldFacade fieldfacade = null;
//Ste 2: Get all field names
String[] allfields = form.FieldNames;
foreach (string mFieldName in allfields)
{ // Loop through each of adobe field
       try{
                    fieldfacade = form.GetFieldFacade(mFieldName);

                    //Break it down & form the json data
                    System.Drawing.Rectangle box = fieldfacade.Box;

                    dynamic adobe_ft = new System.Dynamic.ExpandoObject();
                    adobe_ft.page_number = fieldfacade.PageNumber - 1;
                    adobe_ft.required = form.IsRequiredField(mFieldName);
                    adobe_ft.x = box.X;                   
                    adobe_ft.label = mFieldName;

                    adobe_ft.y = 792 - box.Y - box.Height;
                    adobe_ft.width = box.Width;
                    adobe_ft.height = box.Height;

                } catch(Exception e){
                    if (e.Message.Contains("cannot"))
                    {
                       // Trace.WriteLine("---- Field cannot be found: "+mFieldName);
                    }
                }
                   
               
}//End of ForEach loop

// Step 3:remove all form fields
pdfDocument.Flatten();