I noticed that you now have the FX Aid and Beads. They both have stereo outputs. The matrix mixer was recommended, but it's mono. So that limits you to four mono inputs.
I would go with something that is stereo for your main mixer, like an EMW stereo mixer. 8 stereo inputs, leaving you six stereo inputs for the rest of your rig. Matrix mixers are a nice-to-have item. But not for this build.
https://www.modulargrid.net/e/emw-8-channel-stereo-mixer
Also, there are too many VCAs for the size of the rack. The Happy Nerding or the Intellijel could go and you'd be fine. That space would be better suited for other resources. I like the Intellijel unit. But the Happy Nerding makes more sense for the size of the rack.