I’ve had a frightening number of people do absolutely nothing and not come back to me for years after I’ve done an installation wanting an upgrade. I don’t recommend that.
If you push backups to S3 and have that configuration in your yml file, then the yml file is all you need to recover from a catastrophy.
Mostly you can do upgrades from the web interface, but about 3x/year you need to do a command line upgrade, which is usually as simple as
./launcher rebuild app. Sometimes, it’s a bit more complicated. I offer a service where I do those upgrades when they are required, but I suspect you don’t need that.