Hello,
I am writing a big band piece with 5 saxophones (and a flute, which does not matter here). Dorico creates brackets as follows:

Correctly it does a wing bracket for all reeds and subbrackets for equal instruments.
Now in the course of the piece, the alto 2 player changes to soprano. Here this happens:
There is a subbracket for the single remaining alto sax.
For me this looks odd but I don’t know whether this is according to the general engravers’ rules. If it is, my apologies for complaining
.
Heinz …
I would expect this, because Dorico only brackets the same instrument by default, and the soprano breaks the pattern set at the beginning. To maintain consistent bracketing, you could add a bracketing change in engrave mode.
But I would do without the sub-brackets for reed doublers anyway.
There are options in Engrave Mode > brackets on how to show brackets and braces on single staves. Turning them off there should do what you ask for.
Yes. I checked some full Big Band scores of professional publishers and indeed, they don’t use sub-brackets.