On a somewhat related matter, if I have a StaffGroup with a time-related
footnote in one staff, then the footnote indication gets attached to all
staves at the same time moment, which would seem the desired behaviour,
but that also results in the identical footnote text being duplicated as
many times in the footer as there are staves in the StaffGroup.
Shouldn't the correct behaviour in this situation be for the footnote
indication to appear in each stave (without incrementing the footnote
number), and the footnote text to appear only once in the footer.