Like I mentioned in one of my comments, I'd like to see engineering data comparing non-locking OEM front axle differential housing and a fully lockable OEM front axle housing.
The reason for that is I know for a fact that the rear locking and non-locking differential housings are different!
Also worth mentioning, most IFS trucks out there have relatively easy access to the front differential. This is no the case with subframe/unibody Touareg.
The surgery to install a locker in the front diff would be an undertaking that could potentially result in a catastrophic failure of a design not intended to be locked in the first place.
Also, the proximity of the front differential to engine oil pain which was necessitated by packaging created a potentially dangerous situation in the case of grenaded front differential.
You may find my reference to Toyota IFS front diff lockers anecdotal. And, be that as it may, I've seen some precarious results with modifications of systems not designed to be abused.
The aluminum alloy cast used in IFS off-road vehicles is nowhere near as strong as the weakest cast-iron or stamped center section of a solid axle.
Forearmed is forewarned.
Yes the cases are different because of the addition of the stepper motor to lock the diff, but do you know if the thickness of the casting is different to the locking vs non locking diff? I highly doubt it is. Thicker casting adds more weight to an already heavy car.
If one of the worlds biggest manufacturers of lockers, ARB, makes lockers for many IFS vehicles, Toyota, Isuzu, Hyundai, Honda, Ford to name a few, I'm confident about the R&D that has been done before even starting design.
You keep using words like "grenaded" and "abused". This locker is aimed at the enthusiast that knows and understands the limit of his vehicle. If some clown wants to put this locker in his Touareg and race down the Rubicon he is the exception, not the rule.
I still think the shock loads transferred to the other end of the diff when the traction control brakes a spinning wheel, is far worse than having a constant 50% split of power to both wheels.