is MultiMeasureRest breakable?

[Kieren MacMillan]

Hi all,

I have a piece I'm writing where the piano part is in various time signatures 
(e.g., 7/8 for a while, then 4/4 then 7/8 then 3/4 then 7/8 for a while, etc.), 
whereas the voice is in 4/4 throughout.

Is there a way to break MultiMeasureRests in the voice, so that the piano part 
is spaced "naturally" (as opposed to breaking the piano part in order to fit 
the voice's MMRs)?

Thanks,
Kieren.