Thanks, Steve. Yes, I had, and doing so does save one from exiting to the exposure view. But I wasn't even counting the few presses involved in doing so.
The silver buttons are very nice, but as they involve some mechanical component, I was a little concerned that the repetitions required for each shot might eventually wear them out.
And because the back can't be fired from the live view screen without the expensive remote release (why not?! - that's another obvious improvement to be made) I have to go back to the exposure screen, where the shutter release button is, anyway.
Nevertheless, I'll revisit my procedure and see if that works out better for me.