Having clustering enabled by default is as-designed and this is also applicable for Spotfire environments with just a single TIBCO Spotfire Server. It is
NOT possible to disable clustering.
The Spotfire Server Configuration Tool (\tomcat\bin\uiconfig.bat or tomcat\spotfire-bin\uiconfig.bat) does not give that option, and the
config-cluster command ignores values of the --enabled flag. If the configuration property is added manually in Spotfire Server configuration file (configuration.xml) to disable clustering, it will be ignored by Spotfire Server.