I have had a couple "PENDING RESEARCH" Form 1's. One was for a SBR built on a 80% receiver. After 10 days it went to "SUBMITTED/IN PROGRESS" without me doing anything. 4 weeks later I got my "APPROVED" email E-Stamp. The other was a because the manufactures name on my gun didn't match what was on their approved manufacturers list. They emailed me requesting pictures of the manufacturers name engraved on the gun. I moved to "SUBMITTED/IN PROGRESS" the same day I sent the pictures. 4 weeks to then get my E Stamp. As a weirdness on that one- I received the approval email at 9:16 pm last Sunday (Dec. 21).
For what it's worth- I get excellent pictures of the engraving on guns using a flatbed scanner.