Blank page detections
I accidentally made an exam with an odd number of pages (9). Because I want to print separate files anyway (for staples), and I print double sided this was not an issue with printing (there was just an empty page at the end of each exam). However, this meant that I scanned lots of empty pages, which were detected as scanning errors by zesje. Of course, it could not find the non-existant QR-code. All this is not so much of a problem, as zesje ignores these pages as it should. However, this huge amount of false-positive detected errors, meant that any real scanning problems were not discovered by a simple view of zesjes importing feature.
Could it be possible that (perhaps an option, which I will dutifully copy from exam to exam, as I tend to copy the header of the exams anyway) for exams with an odd number of pages more than 1, each exam gets an even number of pages by adding a page with QR-code (so it won't give scanning errors) and the text "Do not write on this page, it won't be graded" (or some such). This would also make it possible to print the exam double-sided without having to split the zesje-generated pdf in many separate pdfs for each student.