Workflow Activity Completion - Save Changes

Wrt Workflow Activities in Aras, users complete their activity by picking from the ‘Vote’ dropdown before clicking ‘Complete’. 

There is a ‘Save Changes’ option (see below) which allows users to save their comments without completing the activity.  

This option is presently unnecessary and is causing confusion internally - Can you please advise if/how we can disable or hide the ‘Save Changes’ button?