As I said, let me know how your friend gets on. I was told it makes no difference, use of amnesty embassy letter (in the past) means you had/have intent to leave, no long-stay extensions can be issued.
My IO are giving out the free stamp, but it wouldn't help me. I think they would allow me another 30 day embassy letter extension (not all embassy's are giving them out though), but I want to get on a proper long-term visa (like your friend).
Yeah I did, they said because I got the embassy letter extension (like your friend) I could not apply for a non-O or non-B. So it seems once you go down the "extended due to covid" path, you are stuck in that group until you either leave or amnesty extended, and no path out to other "extension paths".