If text has <br>, it gets tspans and wraps onto multiple lines. If you pass the text node to Drawing.bBox though, it is measured as if the text is all on one line, giving the incorrect bBox.

In the example below, the text node is passed to Drawing.bBox. The 304 returned as the width is the sum of the widths of each tspan. When it's rendered in updatemenus though, each tspan is on a separate line.