My Excel 365 VBA application adds Undo and Redo to QAT by RibbonX:
<qat>
<documentControls>
<control idMso="Undo" imageMso="Undo"/>
<control idMso="Redo" imageMso="Redo"/>
</documentControls>
</qat>
Recently Microsoft adapted the Ribbon interface:
How can I grant within XLM or VBA that "Show Quick Access Toolbar" is set?