pamac performs the updates (and the installations of the different packages) within RebornOS. There may be some problem when using it with its default configuration, as it is preconfigured to work with four parallel downloads. To solve the possible inconveniences, these parallel downloads will be adjusted so that they are only one. Also, pamac can work with AUR. If you only use the Arch Linux and RebornOS repositories (and do not use anything from AUR), you can disable this option. In the video you can observe the procedure. Keep in mind that when you select "Preferences" you will be asked to enter your user's password (something that is not requested here, since the demonstration was recorded from the RebornOS installer, where the password is disabled).