I think i can understand what you are trying to say here Andrew but are you certain that a knife will cut deep enough? Would you need to lower the blade as you go or could you fully lower the blade, pause, clear some paper out and keep cutting?
That's true. The blade is likely to only cut about 1/4" at a time, therefore you'll be forced to run the code, then retract the tool and flip some pages, as well as run it again though at a much lower position this time round. You are to keep repeating this until the time you feel that you have achieved all the depth that you need.
I suppose that the blade won't work with rounded corners since its likely to hang up as the cut gets deeper. Try and seeif you can clamp up the pages tightly and do this with a sacrificial board on top, so that you may cut through with a downward spiral. I however can't assure you if that will work.