So I recently picked up a couple of niche audio control modules. They're unusual passive summing boxes/mixers controlled entirely by midi. It's 8 inputs, 8 outputs, and then a summed out. The 8 inputs and 8 outputs are TS unbalanced, with a TRS out that's 1-4 TS and 5-8 RS. If I were to make an XLR patch panel that has 4 XLR inputs that send each channel to pins 1/2 and 1/3 as TS cables, would this result in a 4 channel balanced mono summing mixer?

Just to clarify, you're talking about splitting each XLR input, so that you'd get XL to channels 1-4 and XR to channels 5-8, and then summing them at the TRS out, which is now hopefully balanced mono instead of unbalanced stereo?

I don't know if it'll work, but I'm interested to hear the results.

correct

I actually have 2 of them, so it'd be 4 channels mixed to left, and 4 channels mixed to right, and I'm still searching for 2 more of them.