Netinstall is tough to do for oem system. I would not sell manjaro machine installed with architect without testing it first. Plus it's a lot of work per machine, especially if you run it from iso and don't have pacman cache. For oem purposes, maybe a gui iso creation tool would be more useful? You could test the settings beforehand, guarantee the result and install it quicker on new systems.
I really prefer netinstall, but I think it might not be the best choice here.