Almost always you can get the PKGBUILD file from either Arch Linux Gitlab or the AUR gitlab and just add the aarch64 version of the package to it and then install from that. I have an M1 and M2 macbook airs that I use for home/work and I think the only package I've actually hit a hard stop on is discord, everything else can just be built from source if they don't have a bin version..