Ha I also had this dubious “pleasure” of porting an Elm app to React. @jfmengels is exactly right w.r.t. to the non-obvious mapping of effect handling. The other thing I found was that curiously React-Redux is missing the concept of a dedicated init function. I suppose you are meant to initialise your redux store and then just call your side effects bare… shivers.
Re keeping pace with React: you could always run codemods on the output, so that shouldn’t be that tricky.
One problem I foresee is what to do about the libraries? If I use elm-ui in my project, what is my React code going to look like? I suppose one could simply try to compile all dependencies into a vendor directory, but to make exiting smoother it would be nicer to support some way to “map” elm libraries to idiomatic JS libraries.