Best way to center dynamic markings in a grand staff

Hi there,

I am unsure if I'm doing things the right way, or if there is a better way. When adding dynamic markings to a piano staff (grand staff), I seem to be forced to attach them to actual notes or rests.

To my way of thinking, that actually makes a great deal of sense. But, it does have a downside. As you can see in the screenshot, when I attach dynamic markings to treble clef notes, they are placed "with them", rather than in the center of the two staves.

Is there an approach or setting I have overlooked that would automatically place dynamic markings in the vertical centre of grand staves?