The problem I have with Musicals Week is really that they have all been done to death. Apart from Six, I cannot think of much new really for them to do.
I think I would ask to do something to do Another Suitcase in another hall or One night in Bangkok 
If that wasn't possible, then a jukebox musical number I guess e.g.
a Queen track from We will rock you
a Cher track from The Cher Show
a Dusty Springfield track from Dusty
or an Elton one if Rocketman counts (but if musical films count then This is me Greatest Showman or recycling of Another day of sun would suffice).
I think the much-used numbers from stage musicals (Phantom, Chicago, Cabaret, Fosse, etc) have either been done too much or are iconic (Joe's samba, Georgia's charleston) and the lesser-known musicals are a bit of a dud.
Don't know if these have been done
Can you feel the love tonight?
Seasons of love?
Barnum?
Walk like a man? (Jersey boys)
Stars? (Les mis)
These haven't been used for a while...
42nd street (Katie, Anton used it last iirc)
Big Spender (Louise and Kev)
December 1963 (Rindy and Oksana)
Luck be a lady (Victoria and Brendan)
but yes, for me Musicals week/Broadway is a bit of a damp squib
Unless Hamza does something from Hamilton in which case I'm all in!!!