Currently you can't "insert" on a "mix". So you can't insert a waves plugin via multirack native like you do a channel, but there are ways around it if you want it bad enough. One way would be to route the mix output to waves (example digital out 33). Then use another channel of the mixer to return (example from digital in 33). There are obvious risks of mis-routing and creating feedback loops, but it can be done. It's worked for FX processing on analog boards for years. The biggest down side is that you are running through the console twice and therefore adding more latency. The console itself doesn't add much, but you'll be hard pressed to get each waves insert to have a path less then about 4.5ms plus the console. So if you run a channel insert and then do this mixbus processing you will be looking at at least around 11ms by the time you ad the console and that assumes you have a pretty stout computer for waves that can keep up with your number of plugins at that speed. It could easily be twice that pending the buffer size and particular waves plugins you are using.
Thanks so much for your reply. Ok so just to let you know I am a novice to the waves environment and to using send and returns on a digital desk, always used built in features!
So I haven't actually used or tested the signal from the desk to the Mac for waves and back to the desk to see if it's all working on a channel insert yet, but if it's as simple as selecting the channel/fader and then the inserts menu from the menu screen and then the inserts setup on insert one then this should be fine. I will forget the option to send to a mix bus, but what if I wanted to run a plugin on the master LR bus, say a SSL master bus compressor how would this be achieved?
Sorry to be a pain, but an explaination / understanding of the signal flow and desk routing for me would be great!