For example, if I wanted to self-publish some of my own pieces, or my editions of other composers’ work, and actually sell copies to performing musicians, would Dorico’s output (as it currently stands, but with all necessary and feasible tweaking) be considered up to industry standards, or still quite some way off? Or would it be wiser to have it re-engraved by real professionals?
Considering the, let’s say, mixed quality of a lot of self-published material readily available for purchase online I’d say you have a head start with Dorico, even with default settings. Big-name publishing companies may have more requirements and their in-house engravers might not (yet) accept Dorico files. But more and more do, because the output is indeed more than acceptable. Depending on the amount of tweaking you’re willing to do, perhaps even exceptional. 
I’m sure you can look at most any engraving and Dorico and see that it’s up to industry standards in terms of output. Many members here use the program exclusively for their publishing ventures. I myself am planning a new set of orchestra materials for Massenet’s Werther using the program. I have some smaller, contemporary wind chamber music I will eventually publish as well.
Like any software, it will take you to a point and then give you the resources to take it further if you desire. Dorico, being the newest program and additionally a very well researched and thought-out one as well, I think takes you to the farthest point. But, after that, it’s all up to you about how “good enough” your output is.
Someone will eventually bring up the point, so I might as well bring it up myself—not a lot of the biggest music publishing houses are using Dorico yet, but I think this has near nothing to do with quality of output and everything to do with them having huge archives of works and files which are probably in as few as one program or at least predominantly one program. Additionally, these houses have curated very specific aesthetics and house style guides which, while I’m sure they’re happy with them, frankly evolved alongside some of their programs of choice, which means change is simply a big factor for them. While I think the ease-of-use and beautiful output of Dorico should be enough to get most people to use Dorico, the reality for the largest music publishing houses is they will probably wait until they are forced—perfection of features such as condensing and divisi might ultimately bring them around.
Dorico can turn out a very professional result with very little effort. And considering the poor quality output sometimes produced by major publishing houses, You’ll be doing better than average.
However, if you plan to self-publish lots of pieces, it’s certainly worth your while learning about decent engraving practices, and what sort of results you should be achieving. Rather than spending money paying someone to engrave it for you, invest in books about engraving, buy scores that are excellent examples of the craft. There’s a web forum that specialises in discussion on engraving here: https://notat.io
Thanks for the advice! I’ll check out the forum; but could you give me some preliminary pointers, especially which books to read?
The contemporary “bible” is definitely Behind Bars by Elaine Gould. It’s terrifyingly comprehensive. A lot of the “best practices” from that book have been actively coded into Dorico from the start.
That looks gorgeous.
Thank you, and precisely my point—besides converting a lot of playing techniques to French and fiddling with Engraving and Notation options (including an unusual amount of time perfecting rehearsal marks for this font), I’ve done almost nothing. No true work in Engrave mode—no manual breaks, movements, or anything. Almost perfect!