As amusing and introspective as this discussion has become (one might almost say anal ?) , the preamble just asks us to highlight the flyer and its flight path so I have highlighted the relevant 28 cells and I'm content to leave it at that.
Regarding the doubled up letters, I put the O and R in the NW and SE corners of their cell, and the O and D from left to right in theirs, but we will see what was intended in a mere three weeks.