Tempo button on Agile Board visible although plugin is disabled

Tempo version 7.8 recently upgraded on OnDemand incorporates Agile Timesheet as described in Tempo Timesheets 7.8 Release Notes

This incorporates a new button for Agile Boards:

but when the plugin is disabled or without a valid license, the Agile Board button is still visible but without an option:

Cause:
The "System Plugin: Tempo Core" provides that functionality and disabling the user addon "Tempo Timesheets" doesn't disable the System plugin that is only accessible to system-administrators.

Workaround:

• Request support to disable all Tempo Plugins