Page 9 shows the wedge supports. It refers to them as #12 in the cut list. From what I can see, it shouldnt make a difference that the foot rail is not there.
If you look at page 7, I have basically removed parts (1) & (2). Everything else is identical. Because I removed those parts, I have shortened parts (7) & (8) to make them run flush with part (3). The uprights (11) are still in the same place, flush with the outside so their location hasnt moved. The wedges are supposed to connect the two (11) uprights, so nothing should have changed.
I attached a few photos to see if this helps.