There is currently already a way to get that effect with Videosync:
- Drag a Squares plugin onto a MIDI track
- Set C (columns) and R (rows) to 1, leave W and R to 100%
- Set Fade out to 0
- Create a MIDI clip on the Squares track with a note on every beat, with a length of half a beat
- Set the velocity of all notes to maximum
Playing the clip should give you the effect you describe.
Here is a set in which I have done this: http://downloads.showsync.com/BPM-Shutter-effect-Project.zip
Let me know if this covers your use case or if you have additional requirements (automating the shutter speed maybe?) that are not solved by this approach.