@jayfresh had a few questions, some of which were likely rhetorical or Socratic.

What does "use global tags in autocomplete" mean?

It's an awkward turn of phrase, but the tag interface provides completion based on either the tags used in the current tank or all tanks. So, if the box is checked you get all. I could figured out a good phrase, so just put something in until some feedback led to something better.

Why is it called a tiddler? Do tiddlers float about in tanks?

Very Socratic this one. Jon is not the only person to ask some version of "why are you continuing with the term tiddler?" It has associations for people who have previous experience; associations which may not be true in Tank. For people who have never heard the term it is likely confusing.

I guess the main answers are: sentimentality and that's what they are called in the code. I do want to use a term that is not "page" because that works against the compositional nature of tiddlers and the ideas about associated metadata.

But if it is going to be used, it does need better introduction or explanation.

...is probably a pretty powerful thing, but so far it's not entirely clear to me what it's for

You may be looking for too much. The blurb on the frontpage does pretty much cover the top layer: It's a wiki with a nice API. The Features info gets much of the second layer: it has {trans,extra}clusion, robust authorization handling, notifications.

And then there is a third layer: You can use the API and the storage to build your own stuff, either via comps or Single Page Apps or (because of CORS support) stuff elsewhere.

wonder why the content from the comp isn't loaded into the comp app in some way

I'm not really able to parse this. Comps can load content but they don't have to. Both of the TiddlyWiki comps lost content after loading the app. Same for the bookmarking comp. See, for example, my bookmarks.

What am I missing?