As well as being able to customise the IDE menu for students you can also disable the ability for students to download (Project > Export as Zip) their assignments before completed in the assignment settings. Once the assignment is completed they can then download the assignment.
Be aware that if you also enable Read Only with Resubmit option on Visibility on Completed setting they can mark as complete, download the zip file and change the status to incomplete to carry on working. If that option is enabled, we suggest you customise the IDE menu to hide that option whether the assignment is completed or not.
To enable or disable downloading an assignment, follow these steps:
Open the assignment Settings.
In the Assignment settings, click Disable Download by Student to prevent students from being able to download.
To enable the assignment, uncheck Disable Download by Student.
Click Save Changes.