User Configuration > Administrative Templates > Microsoft Visio 2016 > Visio Options > General > User Interface Options
User
HKCU\software\policies\microsoft\office\16.0\visio\application
This policy setting allows you to configure the Mini Toolbar on selection of text. If you enable this policy setting, the Mini Toolbar is not shown on selection. If you disable or do not configure this policy setting, the Mini Toolbar is shown on selection.