Both Bogaudio Assign and Grande Tails (linked above in the post by MrMoustache) do what Ablaut requested—by rotating through a number of polyphonic channels as each new trigger appears.
This does however require the use of polyphonic oscillators and polyphonic envelope generators.
Thanks for reminding me about those again. Trying with Kontakt and a Grand Piano instrument and it’s a revelation – it handles voice assignment the way most VST synths do, which is perfect for sustained notes within Rack voices. But also it helps VSTs in VCV Host modules sound more natural.
thanks for showing us that that exists! that is indeed what i was getting at. (and i should’ve more carefully read @MrMoustache’s comment…)
i’m aware of poly oscillators. but what modules would you (or anyone else) recommend for polyphonic envelope generators?
All of the Bogaudio envelope generators are polyphonic.
Don’t forget about your VCAs, and filters, and … You will probably want them to be polyphonic as well.
It is simple to find polyphonic versions of any particular category within the module browser. You can select multiple tags by using the Ctrl (or Command) key. For example, you could select Envelope Generators and Polyphonic.
My whole thing compositionally is exploiting polyphony. So I have a whole bag of favorite modules & tricks. In fact Rack’s handling of polyphony is unique in the modular world.
I have some specialised MONO Envelopes because when I did the conversion using SIMD I noticed that using a MONO ENV in a SIMD based module was using 2x times CPU
Thanks for that explanation - I had wondered why you have identical modules other than mono vs poly.
It seems like a good topic for the development category.
I’ll keep that in mind when choosing my envelopes 
Of course I spent a bunch of money on a new computer because I wanted to stop worrying about CPU usage, but there may come a day when I need to worry about that again.
Once you can use 4 Mr Blue Sky in a patch at the lowest audio latency setup, you stop worrying about how much CPU your envelopes use
Can’t you have one module, and run the mono code when only one channel of gate is coming in?
Even if you can, the mono envelope modules are probably baked into 100s of patches so they need to stay…
How does that compare with the VCV adsr? That thing looks pretty efficient. I adapted the code from that for the adsr that’s in kitchen sink. Anyway, Andrew is a pretty good SIMD programmmer.
Oh, I guess I could just measure it! I jacked the sample rate up to 768k to make the numbers big enough to see. Clearly VCV is once again a leader in low CPU usage. Their polyphonic ADRS running one channel has very low CPU usage. (caveat: I don’t know what these modules do, so this may be an “apples to oranges” comparison. I’m not reading anything into this)
