Just went through the certification process (Jan '21) with a very experienced (1000+ planes) and helpful DAR. In Dec he sent me a paperwork kit with the required forms and his instructions on how to fill them out. Much of the information had already been printed on the form. I didn't even know about the online process until reading this thread. He must have taken care of that part himself. Airworthiness was issued on the spot along with paperwork and instructions to apply for repairman certificate. All in all, a very pleasant experience.