According to the manual the current behavior is this: “If you do not specify the interval quality, the interval degree follows the prevailing key signature.”
Yet if I’m in C major, select a B flat note and write “3,5” into the note tools popover, I get a D flat and an F flat (not a D and an F as the manual – in my mind – suggests). It doesn’t take me long to type “M3,p5” instead, but as the harmonies grow more complex, this sort of recurring mental “calculation” can become taxing.
More often than not I would prefer being able to enter intervals without taking key signature/accidentals into account. My workflow would become much more efficient if I could make the note tools popover a bit more “stupid”.
I would expect D♮ and F♮ in that case too. It seems as if Dorico adds flats to the added notes only because the B is flattened, which is pointedly not what the documentation says. I have been able to avoid this problem since I started using a midi keyboard.
I’ve been reading through the code and I believe it is at least doing what’s designed here, but I agree that this kind of transposition that snaps to scale tones would be useful. My colleague Michael, who knows this area of the program best, is away until the New Year, but I’ll discuss this with him when I can.