For `DynamicTextSpanner` grobs there exists the auxiliary `DynamicLineSpanner` grob, providing a vertical baseline to align successive dynamic grobs within a staff. LilyPond provides other such pairs like `CenteredBarNumber` vs. `CenteredBarNumberLineSpanner`, or `SostenutoPedal` vs. `SostenutoPedalLineSpanner`.
Is there a similar auxiliary grob for `TextSpanner`?
Werner
