f89, f102: folds planned, then shifted towards spine?

[Koen G]

I don't know if this has been discussed before, but I noticed something strange about f89 and f102. There may be other foldouts as well, but I found these two the clearest. In both cases, on the recto and the verso (so four "pages"), the scribe takes into account a fold that's somewhat visible on the parchment. Gaps are left in the text block, or the whole block is confined to one side of the fold line. However, in both cases, the actual folding line that came to be used in the codex is shifted inward, i.e. the fold came to be closer to the spine.

   

   

What this tells us is that the scribe planned for a fold, more or less on the location where a previous fold is still visible. But this fold did not become the preferential one, with both sheets becoming more folded inward.

I wonder what could be deduced from this, if anything, especially with misbinding and singulions in mind. Is the current preferential fold required to fit the foldout into the codex? Maybe someone misfolded the flap before storing the MS for a long time? Although then it would be a coincidence that both foldouts show a similar shift.