Which is actually an UAV, designed to attack designated locations the way cruise missile does, and able to return by terrain-hugging. Terrain hugging may not be possible if size increases.
The size of aircraft would be multiplied by 1.5 or 2.0 to make it able to return (to storage more fuel), larger wings too.
This has been thought,i can assure you. MIUS is actually the same, just it doesn't follow the path of a cruise missile but more of an aircraft's.
Wouldn't be possible to use from submarines-surface assets.
Useful if only intended to be used from homeland, but again as complex as an aircraft and will diverge the commonality thus will cause more operational costs.