I have a lengthy command customization that I want to include in LaTeX export. Since it must appear in the preamble,

#+BEGIN_LATEX

...

#+END_LATEX

didn't work. I had to prepend

#+LATEX_HEADER:

to each line in order to achieve my result.

I found C-h v org-format-latex-header RET:

"The document header used for processing LaTeX fragments..."

But it seems that when the docstring says "fragments," it is not referring to exporting.

Are there any customizations to do the same during export?

Thanks,

Jake