Is my ReaR installation on SUSE Linux Enterprise products supported if I modify the bash scripts installed from the ReaR package?

SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Server 15

The supplied bash scripts in the ReaR package don't include linking elements with other parts of my backup infrastructure and the scripts would have to be changed to integrate with my environment. I understand that modifying files installed by a SUSE Linux Enterprise product package renders the system unsupported.

Your ReaR package installation is still supported if you make changes to the package bash scripts to integrate with your environment. ReaR is not provided as a complete backup architecture, it's a disaster recovery framework that complements backup so some assembly required is a supported scenario. See the first paragraph of the latest ReaR documentation:

SLE HA 15-SP6: https://documentation.suse.com/sle-ha/15-SP6/html/SLE-HA-all/cha-ha-rear.html

Although a SUSE Linux Enterprise 15-SP6 reference, the point is valid for all supported SUSE products that include ReaR.

AN EXAMPLE SCENARIO: As an example, in some cases of using a third party backup technology such as NSR it's possible when the NetWorker server identity is discovered automatically that it isn't available information to ReaR during a backup. A possible result using the default ReaR bash scripts is that a backup appears to have completed successfully but a ReaR recovery ISO image is created every day due to it being unknown where the NSR server that accepted the backup is located. This can be avoided by customizing the ReaR bash script layout/save/NSR/default/650_check_iso_recoverable.sh to determine the NSR server for the local environment, or even by disabling the script by placing a return 0 statement as the first active line. There is no actual failure in the NetWorker or ReaR environments, they just need to be managed to be a little closer to each other and the ReaR script that experiences the problem is a good place to make a supported change of this kind.

NOTE: Documentation recommends that the ReaR version should not be replaced on a system when a functional disaster recovery procedure is successfully assembled. That prevents user modified versions of the scripts from being replaced. In contrast when a particular ReaR version does not work for you, try a newer version. It's important to have a record of how ReaR was modified on a host and use the knowledge to make equivalent changes to the ReaR installation on relevant new host installations.

ReaR doesn't include interfaces with one or more elements of my backup infrastructure.