Centered Forest

I have a Diagram with a TreeModel with a forest of multiple trees. I am using TreeLayout.Arrangement=“Vertical” but I can’t figure out how to get all of the root nodes to be centered along the same axis. If I have one tree that’s only a few nodes wide and the one below it has dozens of sub-nodes it looks really terrible.

Is there an easy way to center each tree or line up the roots on the same vertical axis so they aren’t all aligned to the left?

I currently have Diagram.HorizontalContentAlignment=“Center” & TreeLayout.HorizontalAlignment=“Center” but they seem to have no effect.

You are right that those content alignment properties should not affect the layout.
You can override TreeLayout.ArrangeTrees to do what you want. This post will be useful: ArrangeTrees.