You're referring to things as "event handlers" that have nothing to do with events (like dataset and style)... and are talking about objects when this only applies to Element nodes...

So I'm really not sure what you're asking.

As to event listeners, you can either set onevent in an attribute object, or with addEventListener after the fact, so I don't see the problem.

This might become more clear in part 4 of the series when I implement state and a calculator demo. (Hope to have that article up mid-week not too long after part 3. Code is ready, article is not)