Brackets and braces should nest

1. Open attached score
2. Drag a bracket from the palette to the guitar staff
3. Double click and drag down to extend the bracket to the last staff

Result: bracket overlaps the curly brace for the piano part
Expected result: bracket should be offset to the left

I wouldn't mind so much if the bracket could then be dragged, but it can't. There is only a global Style setting for the distance of all brackets to the staff; no way I can find to make these nest.