Though the task be laborious, it is less so (and the resulting score looks better) in Sibelius, now. Curiously, though, I have found something which I did in Finale which it appears I could not do in exactly the same way in Sibelius. As originally notated, the grand balleto quasi uno flamenco often used a composite time signature, 4/8 + 3/16. It seems that such composite meters in Sibelius are obliged to use the same denominating unit note.
I suppose that my workaround might have been 4+4+3/16. But I decided instead to split the 4/8 and 3/16 into separate measures, which yields the incidental benefit of improved flow for the layout.
(As it is, I have other reasons for wanting afterwards to go back to the original scoring, and bring that document into harmony with this "new version.")
The percussionist for the new scoring had been an interesting challenge, and a surprising opportunity. I've pretty much been winging it, so far, in terms of selecting the mallet instrument (where the player is needed for the allocation of pitch material), or unpitched noisemaker in places where it seems an appropriate enhancement to the texture (as it seems a pity to leave the player unnecessarily idle for too long). I've had in mind, though, both timpani for the fullest-textured passage, and a single tam-tam stroke for a key moment ... and to tape the logistics out, it was necessary at last to print out hard copy of the old original.