M4L: Shaper MIDI, but side-chained from other track?

Hey everyone!

I'm wondering there are any common Max For Live devices that accomplish the following very simple thing -- same as Shaper MIDI, but instead of being a MIDI effect triggered by the current track's MIDI events, it is an audio effect which has a sidechain option (kind of like how Corpus, or Auto Shift in Live 12 Beta, allows a MIDI sidechain option).

So, for example, I could have some audio sample playing on Track 1 with this audio effect on it mapped to a Dry/Wet knob on a reverb, then have a MIDI Track 2 where I'm playing some rhythm from a controller, causing the reverb on Track 1 to swell according to my playing.

The same question would apply to the Shaper audio effect, which could also benefit from a sidechain.

This seems like such a basic functionality that maybe it's already included in Ableton and I've just missed it? If not, I might take this up as a intro challenge for coding Max For Live devices myself.

Thanks

~Patrick