Hi Robert, thanks for for your explanation. Indeed that is pretty much what I came up with as well, except:
You are using only 2 analog inputs and that frees up the 2 slots on the main in to send another pair to DSP B basically. If you had to use all 4 analog ins though you'd be stuck with 2 channels total for both DSP's just like me, allowing no parallel use.
Furthermore, as far as I know, you'd be stuck with presets that use only 2 channels of either DSP like that, so you won't be able to use these 4-8 channel ones. I mean, you will be able to use them, but they won't sound as intended. Or maybe I'm wrong and I just don't understand how these DSP channels work.
I find it unfortunate that it seems impossible to use the unit as both a firewire audio interface with all 4 analog ins and a full blown effects processor with 2 parallel DSP's at the same time. I really think 16 main in channels would have helped a lot. Or remove these main in/out blocks entirely and let me route anything to anything, just like the product description says.
As it stands now I cannot use it as a DA unless I want to considerably limit the effects. So I really need to use another audio interface to handle my studio gear.