Q: Does one trim stray hairs of the beard?
A: Once the required length is acquired, the excess length hair can be shaped/groomed.
Allah Certainly Knows Best.
Added note: If one is growing out his beard and the employer pressures him to grow it out in an even (length like) manner; the pressured individual needs the employment as part of survival, then the trimming of that which is less then a fist length can be done. This however is not preferred Islamic behavior. It is a matter of survival. Any person employed by such a company must also look elsewhere for employment. One cannot work for an employer that opposes the rules of the Creator. If employment elsewhere is difficult to attain, then one must practice patience. Trimming the beard or to even it out must not be due to an excuse of keeping the beard short or goatee like, etc.