Bump. Can someone let me know if I can assign reverb to one channel and a combination of delay/reverb to another channel? Or would I be limited to using the same reverb/delay mix on every channel?

Ok MC, thanks for the clarification.  Just out of interest, why is this the case?  Is it a hardware limitation?  It seems really weird to have delay/reverb as a combined signal processing aux.  If it's not a hardware limitation, is there any possibility of RME separating delay and reverb in TotalMix FX?  There's no way I'd normally use a fixed combo of delay/reverb on any channel and I can't imagine why any user would want this.

I think it sounds simpler then it is. 1 extra send bus 1extra return. But it is actually 1 send channel per mixer channel. On my device that would be 26 extra stereo channels, 52 streams into the mixer. This takes bandwidth, processing and ram. Plus I think the reverb is ok for comfort reverb on a vocal. but not mixing etc.

But there is a software solution for this with loopback: a simple vst host and a reverb of your choice. You can even host reverb and delay in it and use the pan for the send to the loopback as delay reverb balance per channel.
Of course you can also integrate an external hardware reverb even more easily, either through analogue in out or spdif.
My hdsp9652 has no FX and I have my delay and reverb set up like this. On one machine with external hardware, on another with a vst host. Both work great and are easy to use once set up.