Just Evan

Is it possible to make an audio device that will receive a midi message from another midi track and send it as a sidechain / midi route signal to a vst plugin?

What I mean is that I have several processing plugins on an audio track and I want the last one to receive a midi message as if the vst were on the midi track.

Hello. 

Is it possible to make an audio device that will receive a midi message from another midi track and send it as a sidechain / midi...

receiving-and-sending-a-midi-in-to-vst-on-an-audio-track

you can always use max vst~ object in a device, and send any kind of message to it from any other device in any track.

Yes, but I wouldn’t want to open vst every time in the max patch, I just want to pass the midi signal from another track through the entire processing chain to the last plugin on the audio track (for example ShaperBox vst), so that it would perceive it as if it were on midi track and receives midi messages directly from that track.

It's possible with the "new" [live.routing] added in 8.6

..but it seems very buggy for now with midi ports.

Send and Receive are working between simple devices you can add before your VST but it involves a little unpredictable latency.

Receiving and sending a MIDI in to VST on an audio track