SQL Server is a complex beast, with many configuration options that can range from recommended to completely avoided.
Since the release of SQL Server 2016, several options that were recommended post-install have been rolled into the default installation options and no longer need to be done, and similar changes were made with SQL Server 2017. Even so, there are configuration changes we data professionals need to make after installation, during maintenance windows, and sometimes even during operating hours, so here’s a handy list of changes that do and don’t require a restart of your operating system or SQL Server instance.
As Randolph mentions, this set is not conclusive. For example, enabling PolyBase requires a restart of the database engine. I believe enabling ML Services technically does not, though I do out of caution because the back of my mind remembers something weird about the service’s behavior if you don’t restart the database engine, but p > 0 my brain made up the whole thing.