There isn't really a lot you can do about this. I use a stock strat and when recording I use the keyboard to start and stop the recording session and turn the monitor off during this time to avoid recording the noise. Not the best solution but it is the only time the noise is really an issue. Once the guitar track has been laid then the monitor can be used as normal. But I understand why it annoys you. I would have hoped the Lace Sensors would have eliminated it but obviously not.

If anyone has used any commercial hum defeat devices that eliminate this problem with single pole pickups I'd be interested to hear about them.