We have Gross Beat but it is not MIDI or audio triggered.
We can link a destination source to be affected by envelopes triggered from notation in the piano roll via either a VFX Envelope generator or from an automation clip/envelope controller and these controller channels can be linked with a layer channel for convenience of one piano roll score triggering both the envelope and the notes of the sample/synth layer but this isn't directly in the mixer itself which would be more convenient sometimes, and again it isn't audio triggered either.
We can have a peak controller which could be called an envelope follower which does react to an audio trigger but this can't design a user shaped envelope.
MIDI & Audio Triggered Envelope Effect Plugin
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