I am representative of Aspose.Cells team.
I am not sure about COR*.tmp files.
However, Aspose.Cells for Java used
to create multiple font related temporary files previously, but this
issue has now been improved in latest version.
Now single or lesser number of temp files are created.
Could you please download and use the latest version:
for Java v22.214.171.124
and let us know your findings?