Hi @Lillie_Harris, thanks for your quick reply.
I have carried out a short search of published editions of canons (ie. rounds):
Some editions indeed engrave canons the “normal” way.
But there is a considerable number of editions (at least in Germany) that prefer vertical alignment, most notably the standard publication “Das Kanon-Buch” by Schott (see the music examples on the product page) and the “Evangelisches Gesangbuch” (the common hymn book of the German Protestant Church, see the example below).
Interestingly, American publications tend to use an approach with one system and initial barline (= systemic barline): see eg. MacDonald, M. R./Jaeger, Winifred: “The Round Book: Rounds Kids Love to Sing” as well as “the king’s singers Book of Rounds, Canons, and Partsongs” (p. 9, 11, 15 …).
Unfortunately, Elaine Gould does not say anything on the topic.
Speaking for me personally, I still woud prefer to engrave canons vertically aligned, since this notation reflects the simultaneity of the voices.
If I understand you correctly, at the moment there is no solution in Dorico for the two problems mentioned in my initial post (ie. hiding the initial barline, and vertical alignment of the barlines at the end of the system). So if I may make a request, I would be happy if these issues could be addressed in a future update of Dorico (the first one might possibly be adressed together with the possibility to engrave incipits mentioned by @dspreadbury in this post; the second one seems to be a bug?).
Thank you very much in advance.