Panniers on front suspension forks
Whether it's possible or not, it's a bad idea.

With any suspended system, there's sprung weight and unsprung weight. Sprung weight is the weight carried by the suspension system, and unsprung weight is the weight that's "downstream" of the suspension system (the wheels, etc). In any suspended system, the goal is to maximize the weight that is sprung, and minimize the weight that is unsprung.

When you go over a bump, your unsprung mass gets pushed up, then recoils and goes down, and this cycle repeats until the energy in the system has been damped out (vocabulary aside: although we casually refer to suspension as "shock absorbers", real shock absorbers only damp out the recoil, not the initial impact). Adding unsprung mass makes that recoil much harder to damp out. If you put, say, 2 kg of rack + bag on your front forks, and another 7 kg of load, you're exceeding what the front suspension was designed to handle by a factor of 4 or so. Not so much in terms of the initial shock (which I imagine can be many Gs) but in terms of absorbing recoil.