The basic principle to expanding the table is to drop the skirt by spining it clockwise, exposing the leaves by spinning the ring clockwise, and then spinning the skirt counter clockwise to raise it and the leaves, (along with the arms and star inside the table) to the base table top height.
: My focus is the function of the skirt, so I intentionally just skimmed through the rest of the table description.
I don't see them, nor saw a description of them, but I would definitely incorporate cam-follower bearings into the edge of your platform where the "threads" of your skirt will be guided. A "true" cam-follower bearing is too expensive, but you can make your own with a cheap bearing and shoulder screw or even a bolt, since the loading is light. Solely to show you what I mean, here is a "true" cam-follower bearing.
The benefit of this is at least-two-fold: 1) it makes the skirt movement much smoother and easier. 2) it permits you to create a non-linear thread profile for increased lifting force at the closing of the skirt, while reducing the number of revolutions required where no force is required.
Expanding on idea #2, the slope of your threads would be very steep toward the top of your skirt, and very shallow toward the bottom. You could even have 2 of these shallow segments for when the table is in the expanded position and contracted position. (I assume the skirt is higher or lower, depending on whether the skirt is supporting the open leaves, versus covering the edges of the collapsed leaves.)
The idea of using dentil molding is in the right direction, except you're just using pre-kerfed wood instead of making it yourself. I think you would be better off making it yourself. Start by making your "cam track" in flat wood, like shown below. You would have an upper and lower cam with a space between them equal to (slightly wider) than your cam-follower bearing. The reason for doing it "in the flat" is because you'll want to make it using a router pattern so you can make (at least) 4 identical copies. (I forgot to mention above that you want at least 4 cam-followers at 90 degrees apart, but even more is better.)
There are 2 different approaches for attaching these to your skirt. Option 1 is to glue them in-the-flat, and then kerf everything at once. This would be preferred, as long as you are able to overcome the single down-side. The down-side is that you need to be more careful when filling your kerfs so as to not "muddy" the walls of the cam with stray resin. (P.S. see "Thick kerfing" below.)
The second option is to kerf these separately, and epoxy-resin them to your finished skirt circle. Hmmmm....I suddenly don't like this option any more, because I just realized you will have the very same "down-side" as mentioned above. So ignore this option!!
Because your skirt is now effectively twice as thick as before, you may need wider kerfs....BUT...that doesn't mean the whole kerf needs to be that wide. Make your standard kerfs just like I described the other day (as though your skirt was only 3/4" thick). Only the inside edge of the kerf needs to be wider. So go back with a second-pass of your kerfing, but at half the previous depth, and slightly offset to make them slightly wider (as needed).