2013-06-06 05:42:54: Created issue 'Simplify page-margin box layout' nickname owned by Simon Sapin on product CSS3 Paged Media, description 'As of this writing, the layout algorithm of page-margin boxes is much simpler and plain implemtable than in the 2006 WD. Still, it is a bit more complex that seems worth for this small feature.
There was a request to redefine this algorithm in terms of flexbox, tables, or something. I think this is not possible while keeping the "middle box is centred" requirement.
I propose closing with no change, unless there is specific feedback on the current algorithm.
non-public [Simon Sapin]