We recently added a new feature to Optical Flares to generate native Motion Blur. This makes a lot of sense because when your light source is moving rapidly it becomes blurred and naturally the flare elements should follow. Sorry for the back-to-back plug-in updates but this one is actually fun!
The feature is simple to use, just turn on motion blur for the layer and comp switch, then adjust the samples in the plug-in Motion Blur roll-out.
The light streaks in the sample video are made with Particular and the light is moving with a wiggle expression.
Remember, too many motion blur samples can be slower so adjust the value as needed for your project.