I mix most of my homemade stuff for surround inside Cubase.
My SFP routing looks like this:
Cubase ASIO 1-6 > STM16S and Celmo Ultimatizer > ASIO dest and speakers.
STM16S panned permanently Left front for asio1 etc.
Then i record all 6 ch back to Cubase.
Before encoding i need to edit those files
(level at least)
Now i have bought VDAT and would like to record to it

The routing i would like, is somthing like this:
Cubase asio1L > 6chMonoMixer ch1 > vdat ch1
Cubase asio1R > 6chMonoMixer ch2 > vdat ch2
.
.
Cubase asio3R > 6chMonoMixer ch6 > vdat ch6
If possible, mono inserts would be welcome if its simple to do, and meters. And midi, and....not much more.
I have seen a lot of different mixers, but not any perfect.
Is there something like this, or is anybody willing to take the challenge of building it.