I believe the language for a Fed to renew on D&R includes "has personal knowledge of the applicant" thus it's difficult to just show up at a FSDO expecting to get a renewal from whoever has the desk duty that day. The exceptions are if you know one of the inspectors, obviously; and some POIs will sign off guys at the carrier they are overseeing - some even will renew FOs that are in the training department. Regular line FOs are pretty much out of luck, just the way it is. Standard disclaimer: YMWV.