It would be nice to finally get rid of blue menu bar while editing..
Maybe you could instead ADD a floating QUICK MENU bar, for most important menu choices.. ( Like pen/ereaser/lasso ,colour, text) Or less even..
OR: Implement a radial QUICK MENU..You could make it accessible via gesture, like let's say : click and hold pen together with ONE FINGER tap or soo..
That would make it posible to write with NO distractions and optimal space