* First
  :PROPERTIES:
  :CUSTOM_ID: one
  :END:

#+name: heading-id
#+begin_src emacs-lisp :var point=(point) :var loc=(format "%S" org-babel-current-src-block-location)
  (format "property %S at %d really %s" (org-entry-get point "CUSTOM_ID") point loc)
#+end_src

#+RESULTS: heading-id
: property "one" at 70 really 70

* Second
  :PROPERTIES:
  :CUSTOM_ID: two
  :END:

Call with all header arguments at the point of execution

#+call: heading-id(point=(point))

#+RESULTS: heading-id(point=(point))
: property "two" at 433 really #<marker at 433 in header-eval-location.org>

#+call: heading-id()

#+RESULTS: heading-id()
: property "two" at 582 really #<marker at 582 in header-eval-location.org>

Another call from a code block rather than a call line.

#+begin_src emacs-lisp :var in=heading-id()
  in
#+end_src

#+RESULTS:
: property "two" at 762 really 762