Marks above and below simultaneously

[Daniel Rosen]

I have my rehearsal marks and metronome marks in a separate voice in the score 
I'm typesetting, and I'd like to get them all to show up both above and below 
the score. The best thing to do that I can think of is to use Dynamics contexts 
above and below, but that throws off the vertical spacing between the marks and 
the top and bottom staves; I'd like it to look as though Score.RehearsalMark 
#'direction = #1 and Score.RehearsalMark #'direction = #-1 were set 
simultaneously; same for MetronomeMark. Anyone know how to do this? Should I be 
using some other context than Dynamics? 

DR