Yeah, this bug has been an annoyance for us too. We’re pretty heavily reliant on S3 for all our sites and apps, especially since we use the rest of the Amazon stack for them. So a nice “migration” guide could be useful.
Although we’ve been having enough headaches with self-hosting discourse (mainly my own fault - I’m not an Ops guy, but I’ve been sort of tossed into the deep end), that we may decide to switch to paid hosting anyways, so it may be a moot point.