Remember the basics. Sight alignment and trigger control must be achieved and maintained until the bullet leaves the barrel. Since it is difficult to maintain full concentration on both of these at once, I recommend the following for timed and rapid firing. Put more thought on trigger control than sight alignment. Another reason for this is that the sustained fire targets are closer or bigger.
Timing is the secret to good sustained fire scores.
This means starting on time, firing in a cadence and finishing the fifth shot just before the target turns away. I tried for years in practice to develop this rhythmic cadence by imagining the stationary target was turning toward me and staying faced for an estimated 10 seconds. I never developed the ability to shoot good sustained fire until I was able to practice with a real turning target. I still have to practice regularly with turning targets to maintain the necessary rhythm to get five good shots onto the target without feeling rushed and thinking about time. I would recommend that you consider buying and using a portable lightweight, battery-powered turning target mechanism.