SEP 14.3 RU2\RU3 does not install on macOS configured with case-sensitive file system: "The installation failed. The Installer encountered and error that cause the installation to fail. Contact the software manufacturer for assistance."
macOS 10.15.x and newer - SEP 14.3 RU2\RU3
APFS case sensitive HDD is not supported at this time. Support for this file system format is being reviewed for inclusion in a future release.
SEP supports case-sensitivity in HFS volumes