Proportioning valves are common on cars but not on bikes. On bikes they are sometimes part of the "linked braking" system. Most racers and experienced riders hate these systems since it is not controllable by the rider directly. There was a lot of R&D put into them and the weight bias of the bike, dive features, tire sizes/traction, ect.....
You could probably physically make it fit just fine but there would be no real benefit from doing that.
I had suggested that a manually adjustable proportioning valve could be adapted to at least the rear to help regulate that rear braking lockup.
Sean