scrwfile
Experimental package that routes \newwrite operations through the .aux file to dodge the LaTeX write-handle limit.
The package scrwfile is a spin-off from KOMA-Script and was part of the
bundle up to scrwfile 0.1.12 and KOMA-Script 3.38. It was moved out of
KOMA-Script because it is an experimental package that is no longer officially
maintained.
scrwfile is a LaTeX package that provides a way to route all
\newwrite-style output (tables of contents and other auxiliary writes)
through the LaTeX .aux file. The mechanism changes how \newwrite operates
and ensures that the “No room for new \write” message virtually never
appears anymore.
The package is hosted on GitHub. See the CTAN catalogue entry for more.