Custom Key Signature Root Options

[GabrielduViolon]

Dear Dorico Community,

I notice that the “Root” drop-down in the “Edit Custom Key Signature” dialog only allows for naturals (no sharp/flat notes). I would like to create a custom key signature whose corresponding scale has a root of Bb. Is there a way to make a key signature with Bb as its root? Am I missing something regarding the intended use of the custom key signature feature? Thanks in advance.

[Derrek]

Isn’t the flat checked in the box below?

[GabrielduViolon]

I thought those boxes were only to specify input onto the staff. One can use multiple accidental types in a custom key signature, so I’m not sure if those boxes can clearly apply to the root note. But someone please correct me if I’m failing to notice something.