The problem is that we break baerenreiter-sarabande.ly. With compression
penalties, it goes from 6 lines to 7 (since ragged-bottom is true,
page-breaking is having no effect here). My preferred solution is just
to set system-count to 6 and forget about it.
I realise that part of the purpose of baerenreiter-sarabande is to test
the line-breaking algorithm and therefore I'm a bit wary of adding an
extra tweak to compensate for line-breaking changes. However: the number
of systems in the Baerenreiter original is not necessarily the optimal
number of systems for the horizontal spacing; it is the optimal number
of systems for the combined horizontal and vertical spacing. I therefore
think it's OK to force the number of systems, given that we've taken it
out of context of the vertical spacing.
What do other people think?