Hi,
one more suggestion:
When in fullscreen and split the current document, it would be great to have scrivener focus on the new document (the one that was “cut off”). Or least to have keyboard shortcuts to navigate documents even in fullscreen (like CTRL-Up etc. in “normal view”). That way you could split when you intend to write a new section and continue writing this new one in fullscreen without having to switch back to normal an select it.
– Eiko