PDF forms saved with Reader Extended → Enable More Tools (form fill-in & save) should editable!
Whenever I use "File → Save as Other → Reader Extended PDF → Enable More Tools (Includes form fill-in & save)" to save my form. The form in the resulting file cannot be edited. Why? This effectively causes me to have to maintain three copies of my PDF forms: One with no form controls, one converted to a form, and one with More Tools enabled.