I don't really understand the .esm/.esp thing- which issue does it solve? I've never done it so I wouldn't be a good person to update the wiki with, but if you've got a consistent working solution I say let the world know! What I posted was just a start - a process that worked pretty well for me. Not necessarily the finished product, though.
It's quite an easy thing, just rename your ESP to ESM, start CK, save it, and the next time you start the CK you will notice, that CK in fact lists it as master.
I don't know how large your worldspace is, but working on a 128x128 thing this is very recommendable, because I noticed that after the third save or so it gets painfully long to save the ESP, including corrution possibility.
As soon as your plugin is an ESM, you can save it as new ESP, which will be 1 kb at first I would guess.
Let's see, perhaps I'll update the wiki page, I've never done such a thing before.