I wasn't able to reproduce that issue, for me the target just doesn't show up. you can lightly redefine the behavior of the export functions like this:
#+BEGIN_SRC emacs-lisp
(cl-letf (((symbol-function 'org-odt-target) (lambda (target contents info)
(org-element-property :value target))))
(let ((hfy-user-sheet-assoc nil))
(org-open-file-with-system (org-export-to-file 'odt "test4.odt"))))
#+END_SRC
you could also use around advices for this.
John
-----------------------------------
Professor John Kitchin
Doherty Hall A207F
Department of Chemical Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
412-268-7803