The only issue I see is with your first premise. It might still be possible to have heavy enough braking that would shift weight to the front even in poor weather, actuating the compensator, yet still not locking the fronts. (Not with the snow we have around here, mind you, but maybe in rain.) It all depends on the surface, tread, contact patch, etc.
With lower than ideal traction, and with load shifting forward, you could actually still get quite a bit of grip with the fronts (more grip, conceivably, than the car in a neutral stance or with very stiff springs or low ride height
because of the very weight transfer putting load on the front tires not only affecting the actual contact patch but the sprung weight applied to those wheels). Yet the back will necessarily have less traction because of that very same factor; and if the backs
do lock in less than ideal traction, once you get any slip angle involved the rear is more likely to keep rotating around than if conditions were dry. This would be even more reason to limit additional force to the rear brakes in poor weather conditions.
My own experience (including some limited track work in a race-prepped 911C4 and
many misspent years in my youth careening into snow banks with various cars) is that poor weather just exacerbates a car's existing tendencies, it doesn't completely change braking or suspension dynamics. The same types of effects will happen as in the dry, just with very reduced forces and much lower speeds, naturally.
The million dollar question, I suppose, is IF there is enough traction in any given situation to shift enough weight forward to actuate the compensator without locking the fronts and losing the benefit of such a system. I can easily imagine that there would be, but it would obviously vary case by case, including factors like the car's velocity, the driver's ability to effectively threshold brake, the car's sprung weight, its ride height, type of coils, type and condition of tires, the quality of road surface itself, the amount and nature of the water, etc, etc. Every situation will be unique.
If you've read this far, I agree with P2 and P3, though.
Oh yes: Socrates was a man.... All men are mortal...
Cheers,
phaetn
