Upload it to the LuCI restore backup function... that'd be spelled out with screenshots.
The point of what I'm thinking of is to dramatically lower the number of steps needed to get a more sophisticated level of function. Imagine if you could go to a site and click a few buttons to say "I want a main LAN and 2 separate guest LANs, with ports 3 and 4 part of guest LAN2 and port 1 a port that will connect to a further AP (ie. become a tagged trunk port) ... etc etc. The questions would be goal oriented rather than technology oriented (like whether you want tags on port 3).
But yes, this should go to a separate thread: how to get started, slightly different from maintaining