Some post install scripts for non-root Spectrum install are no longer available in 10.4.2/10.4.2.1.
Release : 10.4
Component : Spectrum Core / SpectroSERVER
Before starting the installation with non-root account open a case and as ask for the non-root-config.zip from SE. This contains the new documentation and scripts needed for non-root 10.4.2/10.4.2.1 Spectrum installation.
Due to discrepancies in running the process as non root in 7.x version of RHEL like restart use cases, running --user commands, etc. for which we are looking for RHEL support to have a concrete solution to address these issues, the needed steps for non-root installation are not documented on the online Spectrum documentation. We will update the documentation after having the stable steps rather than work arounds.