I have a node with two labels. The primary label is short plain text, and its Visible checkbox is cleared. The second label is HTML-formatted text including < br /> tags to split it into several lines.
When I use "Fit Node to Label", only the size of the invisible primary label seems to be used. So the visible second label is not contained within the boundary of the node. The second label has Placement="Internal: Center", Size="Fit Content", Configuration="Standard", Alignment="Center".
You may wonder why I need the hidden primary label. It's because this is the text that the Structure View uses when listing the node in its Graph tree. If I don't have the simple primary label the Structure View tree is hard to read because of all the uninterpreted HTML markup that displays there.