I already migrated to S3. My upload folder had gone so big that I even could not restore backup(with uploads) on fresh 1GB DO droplet. Now I just need to figure out how to clean my local upload folder. I noticed that avatars are still kept locally, so I can`t just delete all of my local uploads.
Regarding the matter I wrote above. My main concern is that I am maintaining and paying for uploads which nobody anymore needs and there isn`t a efficient way to clean up disk space. Even uploads from deleted topics are still kept on disk. All the occasional pornographic pictures and selfies(which users requested to be removed) from more than a year ago are still kept on the disk. I remember one case where one of my users liked Discourse upload feature so much that he attended to upload a couple chapters of comic book scans to the server. Luckily I was able to stop him, regardless of that there could be lurking around 100MB of comic book upload on my server. These kind of little things will be adding up disk space as community gets older and bigger.
I understand that this really is not a real world problem. Storage costs almost nothing these days and there is no need to cry about couple GB of dead weight uploads. I just saw inefficiency and wanted to share my view of it. Discourse is really powerful community building tool and data usage is nothing compered to the benefits of this platform.
I can report that uploads can`t be deleted this way.