Fixed width measures (or another good way to do this)

[Geoff Horton]

I'm working on some unmetered music that essentially needs to fall
into two columns--cantor on the left, congregation on the right. It
would be great if I could get all the measures to be of the same width
so that the columns would line up neatly. Searching the mailing list,
the only solution I found is to add a row of invisible 32nd notes (or
whatever duration I like) in each measure. Since all the measures
aren't the same musical length, I'd have to do some hefty
duration-scaling to make it come out right, and I'd rather not if
there's another way to do this. Is there?

Geoff