Its simple but got an issue, you need to hack your html. IMO the best approach will be the angular one, just add params to elements, so your designer that is brain less and only knows html can see your template after you put all the logic.

An advice maybe will be try to get as much html friendly as you can, so ppl don't need to relearn / hack html.

I only can give the point of view of someone that uses libraries, not developing libraries, so maybe there is some unknown reason to me for those approaches.

Why not joining Elm instead?

I believe that HTML, CSS, JavaScript should be combined the way they exist in the moment. Elm is too revolutionary for me. :)

do you think that Elm is in the good track? if you are involved with Elm, why I must using it? give me good reasons ;)