p.s. > In this case (as with so many!) the problem isn't moment-bleed, it's > context-bleed: the grace music doesn’t apply to the lower staff, and thus > shouldn’t be included in decision-making there; likewise, the clef doesn’t > apply to the upper staff, and so shouldn’t be included in the decision-making > there.
By “decision-making” here, I mean the “what grobs need to appear in each context” decisions, not the horizontal spacing decisions that would [at least for a human engraver] come after that. — Kieren
