I'm planning to push 0002 (retries in frontend programs, which is where this thread began) and 0004 (add missing locks to SQL functions), including back-patches as far as 12, in a day or so.
I'll abandon the others for now, since we're now thinking bigger[1] for backups, side stepping the problem. [1] https://www.postgresql.org/message-id/flat/1330cb48-4e47-03ca-f2fb-b144b49514d8%40pgmasters.net