Manually controlling key sigs for transposing instruments

For fun, I am entering Stravinsky’s Octet into Dorico. I am coming up against some difficulties w/ the transposing instruments. Stravinsky doesn’t give his trumpet in A a key sig. And for his Bb clarinet, he sometimes does, and sometimes doesn’t use a key sig. For instance, at the outset of the piece, concert key is 3b, and the Bb Cl has 1b (as expected). Then, when the concert score goes to a key sig of 0#/0b, the Bb Cl also has no key sig (i.e. no b/no#). So I’m wondering if it’s possible to duplicate this behavior in Dorico?

Since you can give a player its own key signature (popover shift-K, tonality (or atonal), alt-enter), I suppose everything is possible. And using the transposing overrides in the layouts allows for such a trumpet in A to exist. So yes, you should be able to reproduce such score. Even on an April 1st. :person_shrugging: