If (in ACE) you use an LFO as an oscillator, you can modulate the volume of the waveform (directly within the LFO module) independant from the main envelope. Now, using a slow-ish ramp through the modmapper, you can draw your envelope for amp, filter or anything else, however you want, a bit like the "instrument" page on some trackers.
Go crazy, create volume echoes or filter patterns! Simulate multi-stage envelopes... You can even choose whether to interpolate between graph spaces, turning it off gives you good quantized envelopes and similar chippy effects.
If you then choose "modmap" as the waveform for the LFO, you can have the somewhat fractal situation of the waveform of the oscillator also being it's envelope. I think you have to be a bit of a nerd to appreciate how cool and "meta" that is, but it's there nonetheless
