2 parallel wishbones will only keep the wheels straight when the chassis changes height without changing its angle. When the chassis make a roll the wheel will roll with it..... DAX will prevent that.
I wonder where Sorber has it from. From real racingcars I can think of it but RC cars have many differences with real cars and so you will never know if you do not give it a try.
On another forum he mentioned to focus on the front, if I can create more mechanical grip at the rear I can take out some performing loosing elements like the absurd 3 degrees toe-in and the high spoiler. If I can get this right it will be an advantage in an overal faster car and have no issues with lower mounted bodies as the EFRA want to go back from 170mm to 160mm.
And yes, if it works there is no stopping me try to fix something to the front as well as my friend is busy creating his own 1/5 car with front and rear DAX.