Not that I am an expert on this, I don’t think the N-400 form requires stamped passport copies to be attached as a proof of travel when submitting the application. One must carry the proof of the information submitted at the time of the interview.
Great to know! Dallas too here. I am yet to submit. I will be available for interview only after Nov which is holding me from submitting my application. I see others getting interview letters in 2 months and getting their process completed which is great. I am still trying to decide if I should submit right away and request interview reschedule if I get a letter for interview before I am available. Any info on interview rescheduling?