Even fully open the Motion Control damper on the Yari has a limited oil flow capacity (compared to a damper with a shim stack for example)*. The MoCo allows oil to flow through some holes, where adding compression just makes the holes smaller. The diameter of said holes in the open setting can only allow so much oil to move back and forth in successive hits, so if you bump into obstacles at a certain (high) speed/frequency the fork will effectively get "locked out" after the first few hits.
I used to own a Yari and tried everything apart from changing the damper. My best result was replacing the oil with a ligher viscocity one, removing all tokens and adding about 10-15 more PSI than recommended. This helped the fork stay higher in it's travel where it's more supple and moves more freely overall. Still it wasn't enough for out rocky terrain so I ended up replacing the fork with a DVO Diamond.
So yes, even fully open a basic vs a more sophisticated damper will ride very differently.
*Feel free to correct me if I'm wrong on how dampers work