Ah, I see, I see...

I'm just trying to figure what's in the heart of this function. To describe the bottom line...
Is the following correct?:
-We need a quick way of pointing at a part of the artwork and say: "This is what I need! Gimme that on a page!"
-Sometimes we will need the stuff that's peeking inside the desired 'cropping area' included.
-Sometimes we do not need the stuff that's peeking inside.... So, we need a way of telling that to Inkscape. (Question: Can these two mix?)...
-The 'cropping area' is exclusively(?)/sometimes(?) rectangular.
If it's rectangular, pages are easy to make, if not...

-In the future, this functionality should help other workflows, too?
(i.e. meet some of the needs for print/press workflow (bleeds, slugs, etc), freehand sketches (framing, reframing, multiple frames... think: comics), technical drawings,...)
...
Beh, just to be vile, or for divergent thinking's sake...
A Cookie-cutter layer approach! :) A shaded, transparent overlay mode where we can punch and cut 'windows/holes' that show what's underneath. The cutting borders can overlap and, of course, are saved with the file. Punched 'windows' have various settings available for the artists. For example, whether to use or not the objects that are cut by the 'cropping' border of the window, to add the bleed, etc.  Each 'window/hole' can be saved/exported as a new page/file.

...
Personally, I either layout on paper first, and then define the page I need, or ignore the page completely, finish the graphics and then deal with it somewhere else. I need the pages mostly when preparing for the print, but even then, the trim marks are usually enough for the printing office... That might not be the most common approach at all, tho'... :)
--
Alex