A couple of things I’d want to make clear.
One is, at the point of trying an update by web interface, be aware that the update may fail, and your forum may be down. Be prepared.
Another is, if your host becomes inaccessible or corrupted, you will need the backup files and the yml files. You will need to have them already somewhere safe on a separate system.
To combine the two: always take a backup, and download the backup, before trying an update.