This is a bit of a minefield but it’s only a very tiny minefield. For most containers I’ve ever used the config files don’t get overwritten unless there was a bug in the original. Usually when this happens the change log will have a section labelled “breaking changes”. In fact - it’s always a good idea to read the section called “breaking changes” for any upgrades you do. But - to your original point - in 99.99999% of cases it will leave your config files alone.