I spotted today when I was demoing the table(T80 and 32Rack), that there isn’t delay compensation… For examble I was driving snare to master and also on mono group, byt when I lift the mono group up you get phase shift to higher freqs… Also when I was using computer as same time as the surface… I was doing a test like taking powers down from surface and the audio still keeps coming from the rack, but I wonder why the sofgtware on the computer went also down… It would be good back up otherwise… I mean if you get power down somehow on the FOH, still you would have laptop running the ****…
The comb filtering you noticed is normal when double bussing a signal to one output. This is normal for any digital console due to differing latencies on the two signal paths. Double bussing is usually considered bad practice, is there a particular reason you are wanting to do this? With correct gain structure it should never be necessary. If you are using the group to feed a separate physical output it should be unassigned from L/R.
Some of the digi consoles out there has got automatic delay compensation. A&H should offer this and it should be possible since the delay is the same as they use the same plugs and sub groups throughout the mixer. It is much harder once you offer third party plugins.
with regards to parrallel compression, you could source 2 input channels from the same sockets, so the same signal over 2 seperate input channels then mix the 2 seperate input channels together to create the same effect?
With regards to your other question, connecting editor and the surface loosing power.
To avoid Editor loosing connection if the surface was to loose power. Connect to the mixrack only, this way if the surface was to loose power editor will stay connected as a back-up surface.
Note. Make sure your virtual surface on Editor exactly matches your hardware surface to avoid any incompataility issues