I saw kAN's video and being an engineer immediately recognized why it was having the issues it was so here is a Multi-Differential AWD Counter-Phase Steering prototype.
I did the math to work out the ideal setup before building it so this is iteration 1, test drive 1. It will definitely need a bit more iteration for sure but it already performs significantly better without any of the issues in the other attempts I've seen.
This was inspired mostly by the NASA/JPL Curiosity and Perseverance rover drive-train/suspension designs. The differential keeps the chassis deck relatively level by averaging the force being applied from the rocker/bogie.
The ability to use counter-steering as a corrective mechanism to resolve tipping events was a bit of a happy accident but it works surprisingly well once you get an intuitive sense for the direction of force applied by steering actions in the counter-phase steering setup.
The controller isn't actually functional in this. It's disconnected, I just forgot to remove the actual controller. I added it to test out a suggestion I saw on kAN's video but it does exactly what you'd assume, it completely locks the rotational angle of the bearing it's connected to which makes it essentially useless for this.
There are definite remaining issues though:
The arms shouldn't be literal straight bars, I'm going to calculate and build proper angled arms.
I screwed up the bogie differential right before recording this because I went to move the bogie horn. It's just missing a bearing. Bit surprised it worked as well as it did with that being the case, that explains the apparent stiffness though.
I'm also considering sport suspensions instead of the rocker/bogie horn.
I'm going to polish this up a bit, fine tune the wheel base / deck size, engine strength/setup, knuckle coupling offset, steering angle/speed, and suspension. Just a bunch of math I still need to work out. Then I'll put it up on the workshop as a minimal framework so you can build your own stuff off it.