Updating system in VitalPBX 4 while in HA

Hi there!

I was wondering if anyone has any experience in updating their HA setup system files?
There is a good and detailed guide on how to update the GUI right at the bottom of the HA guide but surprisingly not for the server’s system files (apt update & upgrade).

Is this at all possible once in HA? is it not recommended? what are the risks, if any?