Hi Carl, > extra-offset affects the position of grobs *relative to the staff containing > them*. When the Y position of a grob is increased, it either has no affect > on the location of the staff, or it lowers the staff due to required spacing > from the staff above. Since after-line-breaking is the bottom staff, a > positive Y extra-offset value should have no affect or lower the bottom > staff, to be consistent with positive Y extra-offset for every other grob on > the staff, it seems to me. > > extra-offset doesn’t change the staff-staff spacing parameters, but it does > change the grob locations used in the staff-staff spacing calculations. > > I think this is all consistent, but I could be wrong.
<https://lilypond.org/doc/v2.22/Documentation/learning/moving-objects> says: "extra-offset This property applies to any layout object supporting the grob-interface. It takes a pair of numbers which specify the extra displacement in the horizontal and vertical directions. Negative numbers move the object to the left or down. The units are staff-spaces. The extra displacement is made after the typesetting of objects is finished, so an object may be repositioned anywhere without affecting anything else." From that description, I (perhaps incorrectly?) expect two things: 1. Negative extra-offset [Y-values] in NonMusicalPaperColumn.line-break-system-details should move the system *down*. 2. Such a tweak [in any direction] shouldn't be considered at all in the staff-staff-spacing calculations. IMO, either the documentation should be updated to reflect the reality, or the behavior of NonMusicalPaperColumn.line-break-system-details extra-offset should be modified to match the documentation [and the effect of extra-offset in every other situation]. Cheers, Kieren.
