As I was pouring through documentation from different vendors and trying to wrap my head around how the whole FWF is going to go together, I realized I had never found a location for the EMS module (all of the engine sensors). It has two big D-subs that come to it from the engine, then it connects to the "skyview network" on the ACM. The skyview network is just Dynon's term for their network that ties all of the different modules together. The ACM just consolidates that into one location.
I decided to mount the EMS on the left subpanel rib. I've tried to keep as much as possible out of this area since it'll be covered up by a skin and the only access will be by crawling underneath the panel. There's not much to this particular setup though. If the module were to ever go bad, it'd be relatively easy to deal with even though I would have to lay under the panel. I'll put a hole in the firewall in front of this unit (and a similar hole on the opposite side of the firewall for additional wiring), then I'll probably put a hole in the subpanel to take the wire from the EMS to the ACM.