OK, hacked `org-export-filter-headline-functions' and added the facility to
force exporting a headline on new page by adding a new tag "newpage" to the
headline. Here is the code:
(defun yz/org-export-headline-on-new-page (contents backend info)
"Export headlines with tag `newpage' on new pages."
(when (org-export-derived-backend-p backend 'latex)
(with-temp-buffer
(insert contents)
(goto-char (point-min))
(let ((case-fold-search t))
(when (re-search-forward "^\\\\section{.*\\(\\\\.*{newpage}\\).*\n"
nil 'noerror)
(replace-match "" nil nil nil 1) ; Delete the "newpage" tag
(forward-line -1)
(insert "\\newpage\n")
(setq contents (buffer-substring (point-min) (point-max))))))))
(add-to-list 'org-export-filter-headline-functions
#'yz/org-export-headline-on-new-page)
