It sounds a little like you are going to build a world of stubs. I will admit I blindly built the stub ability as I still wasn't entirely sure what they would be used for but greater minds than mine wished them. I always had the thought of having the ability of stubs to be "sucked" into a main submission somehow or incorporated together in some unique way. But I could still never figure out the overall use of them even then.
I haven't quite grokked the concept of stubs. I just don't know where that boundary is between a stub and a full-fledged submission.
I'm not sure if this fits in this thread or if it should be a feature request (I'm just thinking out loud here), but the idea of having stubs pulled into a sub got me thinking about something I've seen others mention. Some subs are very
long. They can't be split up into multiple subs because they only cover a single topic, but it would be so much easier to read them if they didn't appear on a single page. What about creating a number of stubs and then tying them together with a sub that acts as a table of contents? The stubs themselves would end in links to the next one in the sequence.
To make this idea more concrete, consider MJS's The Keep Beneath the Dusky Star
(a most excellent piece that took me a couple of days to get through.) The sub itself contains only the links to the idea scrolls which provide the actual content. The difference between this example and my suggestion would be to create the scrolls as stubs instead, make the links point to the stubs, and then have each stub link to the next part/chapter.
That could, indeed, be an island made from tying rafts together.