Hello.
Still plodding along, but a bit faster now 
All my typesetting for at least the next six months or so will be purely piano solo.
I will be importing MusicMXL files from Sibelius.
I will be adding flows to the score.
Each flow will start on a separate page, and have its own flow title, with possibly composer and copyright information.
Very important question for me as I am slightly clueless
As I will only be typesetting piano music, should I set everything up for formatting and printing in the full score setup? I may need to set up A4, A3, and letter page pages of the same score.
Thank you for your help.
Paul.
It really doesn’t make much difference, as long as you know which layout you’ve worked on.
For that matter, you could delete the spare layout from the right panel of Setup mode…
If you want three different page sizes for the same score, you can create three “score” layouts and set different layout options for them in setup mode (you might want different staff sizes as well as page sizes, for example).
If the smaller sizes are intended for study scores not for performance, you could just shrink the A3 pages to fit when you print or create PDFs.
As pianoleo said, since most piano scores aren’t formatted like an orchestral part, you might as well delete the automatically created part layout, since you are never going to use it.
Sorry, I am having a senior’s moment.
I can’t for the life of me see how to delete he spare layout.
Could you perhaps provide a screen dump?
Thank you.
Paul.
Select the layout you want to delete in the Layouts panel on the right-hand side in Setup mode. Right-click and from the context menu choose Delete Layout.
Many thanks Rob, and thank you Daniel.
seeya.
Paul.
Dear Paul,
I know why you 've been having trouble with deleting the layout : Delete layout not working as expected - Dorico - Steinberg Forums