Is there any alternative method or ideas which help to avoid this set-up process? The context is to use ubuntu-core images in production environment for embedded devices. If that initial setup process is required then it would incur significant cost.
Note that such a setup is only necessary if one needs to obtain shell access to the device. All the services loaded onto the image will still fire up, so unless your users actually need to be able to obtain shell access, they don’t need to worry about the setup process at all.