Frequency-Tracking Automation Envelopes

I double-posted the Background Services message thanks to an intermittent mouse button, and I can't delete this, so I figured I'd edit it into a tip.

In case you didn't know about this, the Analyst can generate frequency-tracking envelopes. Insert it as a plug-in, click Auto to generate automation, then click on the track's Write enable button. Fun stuff!

I've always thought that was a cool feature, but have never found an actual application for it. Has anyone?

Now, if SONAR offered a feature for copying an envelope and inverting it, you might be able to do some interesting things with complementary EQ. But SONAR's envelope editing features are unfortunately sorely lacking.