If the humans know how to find the babyeaters' star,
and if the babyeater civilization can be destroyed by blowing up one star,

then I would like to suggest that they kill off the babyeaters.

Not for the sake of the babyeaters (I consider the proposed modifications to them better than annihilation from humanity's perspective)
but to prevent the super-happies from making even watered down modifications adding baby-eater values -
not so much to humans, since this can also be (at least temporarily) prevented by destroying Huygens -
but to themselves, as they are going to be the dominant life form in the universe over time, being the fastest growing and advancing species.

Of course, relative to destroying Huygens the price to pay in terms of modifications to human values is high, so I would not make this decision lightly.