I was asked to submit a scan of all pages of my eligible passports from the last five years. This request delayed my application processing by at least a month, possibly even two. However, my application also required additional supporting documents (I got a letter to send those after they processed my passport pages), which would have contributed to some delay, though perhaps not as long as the 7.5 months it ultimately took from submission to the oath ceremony. Still, I don’t see any issue with submitting the scanned passport pages as part of the application process - Knowing that providing this wouldn't guarantee an expedited processing of the case - There are a lot more factors contributing to the processing timeline.