Topic: Summing a stereo input down to a mono output?

Hey guys,

Apologies if this has been discussed before.

I am planning to make a few significant upgrades to my humble home studio which will involve an expansion of my I/O requirements. Originally I had planned to use a patchbay (1 RU 48-96 point, DB25 I/O) for all routing requirements, but now I feel more inclined to take advantage of the RME TotalMix system. I am currently using it with a RME Fireface 800 connected to a iMac, compatibility is fine. Currently, TotalMix is only passing a stereo input to a stereo output (monitor controller), and internal macOS audio (software playback).

So, I have been looking ahead at my soon to be expanded routing requirements and I have a few questions for the TotalMix experts. From what I understand all sends are pre-fade, is this accurate? Secondly, a routing requirement of mine only has mono I/O. In this situation, what is the best way to sum down a stereo input to a mono send, but I need that stereo input to remain stereo for playback and recording into my DAW? I have access to passive splitters and D.I. boxes that can merge a stereo input to mono but I am curious if this can be achieved entirely within TotalMix?

Thanks for the read.