Next week I'll start building a new case of 12 mm plywood. It's going to be 126HP 2x 3U. In the middle I plan to make a 500 wide free strip of plywood. It's going to be the cable 'highway'. Modules on the bottom with jacks on the top and vice versa so all cables can route neatly through the middle and modules are nice and accessible for play. I plan to bolt 3 6HP panels onto it with some very basic passive functions that I can always use, like mults, cascaded mult, A/B switches on the ends and an internal routing of 8 jacks to the other side to save on cable length in a pretty wide case. in blue I sketched the connections that I want to solder on the back. Now my question is as follows. What do I do with the ground wiring? These seem to be the options to me:
A) don't connect the grounds at all
(some of the 8x portal modules are connected with CAT network cables, these have 8 wires so I think only the tips are connected by these modules)
B) connect the grounds locally on the left and right sides seperately, so 8 on the left connected to each other and on the right side same
C) connect 8 grounds per side and have 1 connection for ground between left and right
D) connect each ground to the corresponding one on the other side just like the tip connectors. Meaning 16 wires go from left to right

I really have no idea which option to choose. Do any of you have experience with this?

In my opinion the best option is to wire up each pair of jacks with shielded cable. That would mean 8 coaxial cables going left-to-right.

Do you mean actual coaxial cables or just 8 bipolar ones?

Actual coaxial. The point is to shield the signals against interference and cross-talk.

Thanks