An interesting observation on Quire 13

[Anton]

There is one serious consideration which seems to have been forgotten here.

If the scribe indeed went for the bifolio model, with the bifolios not to be bound on the folio-basis, then why does the text not follow this model and is put down as if the stuff needs to be bound on the folio basis?

There is a good example of f101, where the text flows across two adjacent folios of a tri-folio, both in the recto and verso sides.