if your trying to find an OS that is low on resources, there’s only one option: alpine linux. Yes it starts out as a TTY (no graphical environment) but they do have scripts to install the OS and a graphics environment of your choice.
the one concern is driver support, generally (unless using a popular distro such as zorin OS) driver support for Chromebooks are limited. I’ve tried getting alpine Linux on my Chromebook and can’t because the wifi card would not work for it.
that said, if you’re ready to manually configure driver support for it (which most likely will happen) the artix OS uses about 128 MB of memory. That said, if you have more, Linux will dynamically allocate more for core OS functionality


more importantly, they don’t recommend that users use the AUR repository (that isn’t to say they are opposed to it). Some advice they have given is to review what the dependencies are before executing the package with an AUR helper or manually.
Just to make a point, there is a surplus of these non officially supported (from OS developers) repositories, such as the terra repository for fedora. It has the same vulnerability as AUR, and yet that is targeted for new users.
Much like how fedora doesn’t officially support Terra, arch doesn’t support AUR. There is a reason why it’s called AUR (arch user repository) over ASR (arch supported repository). AUR entails that it is not supported by arch.