I exported a full score as pdf in Dorico 4 (a file created in 3.5 rather long, 360 pages) and all signposts are showing! I don’t recall that there’s an option for this, and I am sure I didn’t change any options in Print mode. Is this a bug? The print window certainly wasn’t showing the signposts…
I can assure you that the View options option is off by default, and if it’s switched on in your project, it’s because you (or somebody you work with) switched it on.