Install RancherOS from a different ISO that the one used to boot

Hi there, I am building a custom version of Rancher OS and I realized I can’t boot from the iso if I add too much services on it.
So I am wondering if there is a way to make ros install use a different iso than the one used to boot.

Basically I’d like to have one usb with a lightweight version of RancherOS (enough to launch ros install) and one with a full install that will allow me to deploy all my services.

Is there something like that already implemented ?