controlling the spacing *above* a context

[Kieren MacMillan]

Hello all,

I often run into the situation where I have to control the spacing *above* a 
context, independent of what context is there.

For example, consider a choir score structured as follows:

    ScoreMarks
    ChoirStaff <<
        SA-Lyrics
        SA-Staff
        SATB-Lyrics
        TB-Staff
        TB-Lyrics
    >>
    ScoreMarksForReduction
    Reduction <<
        ReductionUpperStaff
        ReductionLowerStaff
    >>

I want to control the amount of padding *above* the ScoreMarksForReduction 
context. I believe my only choice currently (v2.19.x) is to attempt to control 
it via the padding *below* the ChoirStaff. However, it is a known issue 
(“feature”?) that the TB-Lyrics context is not considered in the spacing 
engine. And VerticalAxisGroup.nonstaff-unrelatedstaff-spacing doesn’t solve the 
problem, becuase the spacing changes when lyrics are present versus when 
they’re not. So I need to fiddle around with a new context (“LastLyrics”), etc. 
etc. 

All this fussy coding would go away if I could use something like

    \override VerticalAxisGroup.above-[non]staff-spacing = …

How difficult would it be to implement this feature?

Thanks,
Kieren.

———————————————
Kieren MacMillan, composer
www:  <http://www.kierenmacmillan.info>
email:  address@hidden