Hi Raymond,
What Steffen said is of course correct.
Or do you mean: Can the insertpoint can be switched from pre processing (pre gate) to postprocessing (post comp) like on some other digital consoles?
Then the answer would still be no. You could, however, send the channel to a group and use the group´s insert point as “post”.
And the matrices follow the same architecture as the group and aux busses. They can be mono or stereo, but their number is fixed. So 3 mono or 3 stereo matrices.
cheers,
André