Although Solus is an rolling release OS, having 1GB update after fresh install is a nightmare for user with bad internet connection.
I know the team are busy with Solus 4 and will release a new image when it done, it should be great if we can have an automation ISO build later.
P/s: I don't know anything about building an ISO image but quite familiar with CI/CD system and willing to help testing installation on VPS or my real hardware.