Since there are only four sub groups, which are typically linked into two stereo sub groups, can we add the ability to route a flex bus to a sub group? For example, if I route my drums to a stereo flex bus for processing, I want the ability to send that stereo flex bus to my stereo instrument sub group to further process with the rest of my instruments. I typically use sub groups A and B as my stereo instrument sub group and sub groups C and D as my stereo vocal sub group. This allows me to process the instruments separately to carve out room for the vocals.
Another example would be sending my bass guitar input to a mono flex bus for separate processing and then sending both that mono flex bus as well as the bass guitar input channel to my stereo instrument sub group. In other words, parallel processing without using an additional input channel.
Thanks for your consideration.