I’m not sure if someone already had this idea, but anyway…
Blue Cat Gain Suite http://www.bluecataudio.com/Products/Product_GainSuite/ is free sets of gain plugins, sort of Sonalksis FreeG. But it supports MIDI input!!. So here my VCA
Insert Blue Cat Gain VSt in Insert slot 8 (or what ever you need). In the plugin GUI right click and select Instance preset. On the MIDI tab deselect Use Global MIDI and enable Midi In for Gain, choose desired MIDI channel and Controller 7 for volume. ( you can now control different groups on different MIDI channels) Now you can add more GainVSTs and link them ( Groups A,B,C or D)
Add Midi track and select MIDI out to you desired Gain VST insert ( I use the first instance i.e Overheads)
Now all the Gain VST plugs will ride together when you moove your MIDI fader.
To default GainVST and MIDI fader to 0, or better said to the position where your audio faders have 0 to avoid confusion (unfortunately GainVST always defaults to +0.5 or -0.5 DB, probably due to only 127 MIDI steps) insert MIDI Transformer into Midi Inserts and multiply the Value 2 by 0.650
The resulution of the GainVST fader rely on MIDI steps, so only 1dB changes a possible. I’m still experimenting with MIDI transformer macro to let the GainVST fader work in smaller steps, but for now it works for me
Hope it makes sense what I wrote.Have fun with VCA in N5.
Maybe we could ask Blue CAT developer to add more groups and make the fader resolution finer.