I wonder how people grade booklet panes of 6. The booklets prior to Scott 600 or so tend to always have one column or row of stamps very close to the edge. Some stamps would grade VF-XF and then some would grade Fine or less if against an edge.
I see VF listed for some and then have seen F-VF for stamps with clear margins.
I guess the real question is how does Scott grade booklets.
This is a difficult subject that I struggle with too. I have no idea how Scott grades them.
I will tell you that a former booklet dealer I know told me that centering of the margins between the stamp designs and the far left and right edges and the bottom edge (from the pane cutting) are supposed to be more important than the perf centering, but I don't know if that is a widely held opinion.
A further problem with these booklet panes is that the spacing of the rows of horizontal perforations rarely matched the stamp design spacing (possibly due to issues with wet printing), so you could get one row perfectly between the stamps and the next row of perfs would be off.
Also the I think the intended bottom margin height was rather small and it is quite common to have that edge touching the bottom of the design, and I would think that woould be a lesser sin than touching the left of right edge, but I don't know if others would agree with me.