Gemini Mini Orbital Bertha plume appears bugged, is gigantic and blinding

[Starfire70]

The plume for this relatively low thrust engine is huge. At close range, it's an eyesore of a varied blinking white cloud, at long range it's blinding like the business end of an acetylene torch. I looked at the config but can't figure out what is controlling this.
Is this intended? How can we get this down to a more reasonable LR91 type plume?