negoversial
Something that can be described as being between controversial and negative. It diplomatically expresses substantial doubts without holding an absolute position about what is being said.
"Flying is a negoversial mode of transport referring to its effect on climate change."
"Testing a new nuclear reactor technology close to a city is at least negoversial (=probably not the best idea).
"Testing a new nuclear reactor technology close to a city is at least negoversial (=probably not the best idea).