Overall this looks to me like it is replicating functionality that already exists in the language, but his overuse -- and misuse -- of technical terms makes for a very confusing read.
I mean, what he's calling "receptors" I would be calling "event handlers"; as evidenced by his heartbeat example, where again I'm not seeing anything being done that warrants the presence of or even uses a library! I mean, I'm not the C#'est programmer out there as i consider .NET a technological dead end.
What he calls accumulated carriers I know as a FIFO message stack. What he's doing with multiple "receptors" I learned as multi-recipient messaging.
... all things I was doing three and a half decades ago in assembler and didn't need some goofy library to make happen. That his code examples on their own seem to be as large as I'd have without the library makes me question just what it is he's doing; much less why such lofty techno-babble is being thrown at it.
I could swear I've seen this before, or something very much like it where the guy abused the word "semantic" in reference to something that had absolutely nothing to do with semantics, to the point the word semantic was semantically used so many semantic times on his semantic page it was semantically ridiculous.
Oh hey, this guy does talk about "semantic meaning", and again in a situation where there are no predefined meanings so the terminology doesn't even apply. There's a reason I don't refer to how I use classes and ID's as being "semantic" even if it follows the same philosophy of saying what things are, not what I want them to look like. The UA has no clue what any of it means as there's no predefined spec for it to follow on them.
Reading the whole thing, I cannot quite fathom what the point of it is either, apart from taking something simple and making it as hard as possible to accomplish. In that way, I'd be more tempted to call whatever this is a "framework" instead of a "library" since that's usually the distinction. Libraries are just sets of helpful functions. Frameworks take the simple, make it LOOK simpler whilst making the actual task harder to accomplish resulting in more work.