If I understand your question correctly, you are trying to center the PointMark directly beneath the ItemLabels. If i am wrong, provide me me with some more detail (your code would be extremely helpful) and I can help further.
If this is what you are asking, then yes it is possible to style the template however you like. This documentation
describes how you can style the ItemLabels directly. You can also learn how to style the PointMarks here
The part I think you should focus on is this:
- represents the container for the labels inside the plot area and is of type LabelsPanel
You can find it's definition here
, inside the ChartAreaStyle.
That link brings you to the documentation of the entire structure of the chart. It also shows you how to define your own custom style for your chart.
From there you can create your own custom style, which contains the new ItemsLabel you're looking for. If you need additional help provide me with your code and I'll dig in deeper with you.