Fable isn't just for view logic. Fable is also really handy for writing puzzle solvers/generators for the browser. I used it in https://vowels.io while using regular preact/js for the views. I found that keeping the fable stuff isolated to lib code gave me less friction.
my experience was the same, although is it possible to do everything with Fable, it works better to glue frameworks with typescript and keep F# as library or some function calls in strategic points.
