Changing the output of sce-update is simple, and we can do.
It seems that if we use the /tmp/work contents of the update session, if there is an update to perform, then using that /tmp/work for sce-import is possible. May not be the total "pulling up by the roots" of the code that it first seemed to combine sce-import and sce-update. Just a hidden flag for dCore to use during sce-import that does nothing but use the contents of /tmp/work bypassing the other functions that are usually necessary to obtain the /tmp/work info. Since the /tmp/work data is created by sce-update.