I saw this a few years back and was seriously impressed with the idea, not just as a JS library but the concept of interactive (or reactive as Brett calls them) documents. This is where HTML should be going as a form of media, armed with the question, "what can HTML do that other forms of media cannot?"
But a lot has changed since then - has this been superseded by client-side libraries with two-way data binding? e.g. angular or knockout. It would probably be quite trivial to duplicate the functionality in either of those libraries.
If what you're looking for is exactly what the example on the website shows (say, an interactive textbook), then I would just use Tangle because it's ready to go without much effort on your part. But if you wanted more flexibility, then of course you should use a move advanced library like Angular.
I don't think it would be a big ask. Dependency tracking/resolution and two-way data binding is baked in, so you'd only have to create some ui components (e.g. a slider) to allow for altering of the values and everything else would just work. Though if you wanted to do it properly you'd probably encapsulate the functionality in a directive of some sort.
But a lot has changed since then - has this been superseded by client-side libraries with two-way data binding? e.g. angular or knockout. It would probably be quite trivial to duplicate the functionality in either of those libraries.