That the object could have outgassed 10% of its mass while exiting the solar system and produced a steady acceleration with no detectable change to its orbital

That the object could have outgassed 10% of its mass while exiting the solar system and produced a steady acceleration with no detectable change to its orbital period stretches all believability. However, I've seen similar bullshit pass as explaining such cases consistently in this field, and if anyone doubts it or makes an issue about it for too long, they get the old peer pressure applied to get them in line, or end their career. I think that is part of where the vitrol comes from. People don't like being silenced or losing their respectability because someone waved their hands a lot and said they explained something.