Bass Clarinet - Bass Clef at concert pitch, Treble Clef when transposed

I'd love to see the addition of an instrument that is a standard Bb Bass Clarinet, but it uses the bass clef when written at concert pitch, and it uses the treble clef when transposed. It's possible to fiddle around with the clefs and make this happen, but it seems unnecessary as this way of writing for bass clarinet is commonplace.