forcing a V.S. page turn with ragged bottom

[Kieren MacMillan]

Hi all,

In musical theatre (and some other situations), it isn’t always optimal to have 
all pages full of music — in particular, the layout may be such that it’s best 
for the performer to turn the page one or more systems “early”. In such cases, 
it’s convention (at least in musical theatre scores) to put a marking — often 
“V.S.” — in large bold text, and leave the remainder of the [vertical] page 
blank.

Is there a “natural” way to accomplish this in Lilypond? I’ve been using the 
edition-engraver to inject a markup with “[effectively] infinite height” in the 
last measure before where I need the page turn to be… but it would be even 
better if there was some mechanism where the user could write

    \VS

and it would add the markup, force a page turn, and not try to fill the page 
[if ragged-bottom is set to ##f].

Thanks for any thoughts or code!
Kieren.