Why dont we see this anymore on synths? The last time I saw it was when I owned a Casio VZ8M. Now that the Virtual Analogs and the Physical Modelling synths are here (notably the Alesis Ion - only 8 note poly), wouldn't it be a good idea to bring it back?

What exactly do you mean by MIDI overflow?
I kinda understand you there, but before getting into deep dicussions I just want to make sure that I understand you correctly.

-ED-

What I mean by Midi or Polyphonic overflow is that you could link two Prophet VS' and get 16 note polyphony. You could link upto eight Casio VZ8m's to acheive 64 note poly. That's what I mean by this function.

That's what I thought.
I'm surprised to hear that nowadays synths lack that feature. Especially if the synth only has 8 notes polyphony. It's about as stupid as it gets.
I mean, they pack nowadays synths with everything under the sun - there's no intelligent reason for not having that function.

I use it a lot with my JD990s and some older
Ensoniq modules. Most of my newer synths have more then enough polyphony, but even they have "midi overflow" (or Stack 1 of X on Rolands)
Strange...

-ED-

I could be wrong but Ive known that to be called poly-spill or Polyphony Spillover.

I have known MIDI overflow to be something entirely different whereby usually a bandwidth bottlenecking occurs on any one particular device, typically like when a large system exclusive change(s) message is going thru that device to another one later in the chain and the amount of bandwidth exceeds the capacity of the thru devices port. The overflow causes whatever data that went over the limit to be ignored.
Hell i dont know these days....um i'm claiming ronny reagen on this one.