I have never seen a de Dion on the front. The usual layout is the hubs connected by a rigid frame so they are always parallel, with a frame mounted diff and cv axles. Some form of hub location must be used to retain fore/aft hub location. The primary advantage is reduction of unsprung weight (the diff). There is a risk of overrunning the angle limit of the cv axles in an offroad vehicle.

If I understand you corresctly, you are spring mounting the whole IFS. You have a really large unsprung weight that way. I see no real advantage over sas, Now, if the original a arms were still functioning, you'd have more front travel, but would have to have some spring suspension on the a arms (coil overs?) and two sets of shocks, and on and on and on.