Peace Brother! I read it, and went to the relevant sections on the KPA, I probably explained poorly. The big point is, I don't want ANY of the direct KPA guitar signal to show up in the headphones unless I choose it. But, I want the Main Outs to still have guitar. Currently, whatever is the Main Output source will show up in the headphones.
The reason this matters is that it means one less piece of gear for the in-ears. Instead of using a wired headphone amp like a Behringer P1 I'd just use the KPA's headphone amp.
Yes, there will be some latency from the mixer (XR18), but I want the option of a pure signal from whatever source I choose and the ability to adjust. So, it is very likely that I would use the KPA into the headphones, but I'd need to adjust the mix between AUX and KPA/guitar.
Any clearer? (Thanks for taking the time to consider this.)
Best...H