Maybe something pertinent is that the core image of Silverblue which is built and available on an official server is actually in existence as you seem to be inferring. The difference in what is that base image or commit of SB and what is on your system would depend on layering only. As a result, when update time came, if you had no changes by layering or disabling base packages of the commit, you should be able to just switch to the new commit and not build local. If I’m understanding your point correctly.