When I got mine all I needed was passport, copy of passport, copy of entry stamp and extension stamp, copy of TM.6, and then the usual forms for an extension plus the form to request for Covid extension. But I also had my TM.30 and copy of lease just in case as others has mentioned they were asked but they did not ask me. Was very simple and straight forward for me. Under consideration stamp for 10 days or so and that was it. But it seems to depend a lot on the immigration officer so I would just come prepared :)
also, usually if there is a problem with your application, they would tell you when you apply, so once you're under consideration, it's pretty much a done deal. To note is that the Covid extension starts from the day you apply. Not from the end of your previous extension.
yeah, usually after 10 or 15. But even if they deny it, which is very, very unlikely, they would give you 7 days to leave the country after the under consideration period. so you would not be on overstay either way.