I've pushed the changes. If you are interested in the usage, have a look at this test:
If you are interested in the TypeScript behaviours that need to be worked around, have a look at these experiments:
I've make some changes to the README and will publish a new version later.
It would be simpler to just use an array of action creators - rather than a rest parameter - but mixing array and non-array signatures is something I wanted to avoid. And, who knows, maybe the TypeScript behaviour might change, some day, to better suit this.
Another alternative could have been to use an API something like this:
ts on(foo, bar, baz, boo).reduce((state, action) => state)
Doing so would have made things much simpler.