As an MWE, I can test with "emacs -Q" and the following org file:
#+PROPERTY: header-args :eval never-export
# (setq org-export-use-babel t)
#+BEGIN_SRC emacs-lisp :results none
(org-babel-do-load-languages
'org-babel-load-languages
'((shell . t)))
#+END_SRC
#+BEGIN_SRC sh :results org raw
for i in $(seq 200); do
echo ""
echo "#+BEGIN_SRC sh :results output :exports results"
echo "echo 'hello, world'"
echo "#+END_SRC"
echo "#+RESULTS:"
echo ": goodbye"
done
#+END_SRC
#+RESULTS:
Execute the first code block to allow execution of the second. Execute the second code block to generate 200 more. Export. It takes ~6 seconds on my machine, which seems long but is bearable. Based on the profiling, I think the reason it takes 1 minute is because the code blocks use <<noweb>> blocks?. I can verify this with the following MWE:
#+PROPERTY: header-args :eval never-export
# (setq org-export-use-babel t)
#+NAME: foo
#+BEGIN_SRC sh :results verbatim
ls
#+END_SRC
#+RESULTS:
#+NAME: bar
#+BEGIN_SRC sh :results verbatim :noweb yes
<<foo>>
#+END_SRC
#+RESULTS:
#+NAME: baz
#+BEGIN_SRC sh :results verbatim :noweb yes
<<bar>>
#+END_SRC
#+RESULTS:
Repeat the BAZ block with the <<bar>> about 100 times and export this, and it takes a long time. I killed it after ~30 seconds, because I think I have my evidence that :noweb yes is the culprit for the slow export.