Upgrading
Unpack the new release on the server and run the installer again, the same way,
without --light or --full:
sudo installer/bhpanel-install.sh all
On a server that already runs the panel it upgrades exactly what is installed there — Full's extras only where they are present — whatever was chosen at the first install. It never removes anything.
Operating-system updates
Server › Update lists pending AlmaLinux updates and installs them. You can also let it install them on a schedule, and reboot for a new kernel in a window you choose.
Adding components later
A Light server can add any Full component — another PHP version, PostgreSQL, MongoDB, Node.js — from Server › Services, one button each.