[DiapDealer]

I guess I don't see the difference. Starting PageEdit from the opf in Book View has no advantage to opening it via the the External Editor button/shortcut. You get to exactly same place where you can copy-edit and proofread regardless of the path taken. Just because you never used Book View for anything has no bearing on the fact that you are essentially using PageEdit in the exact same capacity as those who can't live without Book View.

Don't get me wrong... if it's just muscle-memory at this point--I get it. But regardless of who things were implemented for, there is literally no difference in how you're doing it to using the external editor shortcut. The result is identical. Except for the fact that the latter will work without having to make sure Book Browser has focus first.