I have found something about the harddrive's use of pong projectiles
The events in the original downloaded save I got from mediafire have (0, 0, -1/1) Pong (0, 0, -1/1), which causes the projectiles, though firing in the same direction, to fire at different speeds. I set up some third-party test arrays and found that (0, 0, -1/1) Pong (0, 0, 0) make them go in the same direction and at the same speed, and so I applied this to a modified drive and got clean output.
I still have yet to get the hang of setting up proper writing arrays, but this is my contribution for now.