Sibelius introduce a very helpful tool called ‘Make into Part’. It brings all the percussion lines into one part which is standard for concert band and orchestra music. Please let me know if Dorico can do the same. I can’t post a link in this forum but if you look up Make into Part for Sibelius from their October 2022 update, it eliminates all the mapping and automatically condenses the percussion lines into one part.
You can tick all instruments in Setup mode on the left side that should go into the percussion part on the right side. So no real need for a “make into part”.
If you want percussion to be on separate staves in one layout but on a five line stave in another…
A) make sure they are all in a kit
B) change their presentation type in layout options for the respective layout
That new feature in Sibelius was only necessary because the previous month’s release introduced an inelegant way to handle nested staff labels that requires you to use single instruments with multiple staves, thus creating a new problem with dynamic parts. I don’t think it’s a feature to especially aspire to, though I can see some value in being able to create a new layout based on a selection of instruments in the music as an alternative to doing it in Setup mode – but it’s already exceedingly quick and straightforward to do in Setup mode if you have need of it.
You can already achieve a single part in Dorico containing all your percussion instruments simply by assigning them to the same player.