I found a number of improvements using 2.24.0, but one irritant is still there: before acciaccatura marks such as caesura and key changes are spaced differently, and so don't align with those in other staffs. Here are two simple examples.
-- Owen Dr O V Le Blanc
\version "2.24.0" \score { \new PianoStaff << \new Staff = "upper" \relative c' { r4 \caesura \acciaccatura { d16 e } d4 } \new Staff = "lower" { r4 \caesura r } >> } \score { \new PianoStaff << \new Staff = "upper" \relative c' { \key a \major r4 \key d \major \acciaccatura { d16 e } d4 } \new Staff = "lower" { \key a \major r4 \key d \major r } >> }