How to use idQ/xmlns in Office ribbon fluent customUI to make duplicate instances of custom controls

I would like to avoid having to create duplicate copies of a custom ribbon control that I want to appear in multiple places in the Office UI and instead create it once and then use the qualified control id mechanism instead. I know how to use idQ to create a shared group across multiple add-ins but can it be used to share a control within the same add-in?

The example below has a custom namespace defined as mns. I then create a group containing the first instance of my control, a button with id ButtonTest and a second instance using idQ but it doesn't work.

<customUI xmlns="http://schemas.microsoft.com/office/2009/07/customui" xmlns:mns="MyNameSpace">
    <ribbon>
        <tabs>
            <tab id="TabTest" label="Test">
                <group id="GroupTest1" label="Test 1">
 			<button id="ButtonTest" label="Button 1" onAction="OnAction"/>
                </group>
                <group id="GroupTest2" label="Test 2">
 			<button idQ="mns:ButtonTest"/>
                </group>
            </tab>
        </tabs>
    </ribbon>
</customUI>

Is it possible to use idQ/xmlns in this way to duplicate copies of controls in the same customUI definition?