It didnt take Elenelen long to ramp right up to 500mhz with simple vrm heatsinks. Imagine what we could do if that cooling tower, thermal blanket, and that stupid bar were all gone, and replaced with an H2O cooler. the vrms, and any heatsink you put on them would then have excellent exposure to airflow.
That's all fine and dandy. But it's a complete waste of time and money this late in the game. Any tiny bit of performance you might gain is eaten up by miner downtime and the cost of additional parts.
If your Neptunes are running... just let them run.