I ran two into one right after the master cylinder, and then split again at the rear axle. I used extra long flexible hose at the backing plates, in a U shape turn, to allow pulling the axles far enough to change punkins without opening the brake lines on the salt. Poor mans quick-change.
This was a handbrake actuation, using a clutch pedal 'under-dash bracket' turned upside down for a pivot.
I am not a big fan of foot operated brakes in a salt-flats car. The fireboots are too big, the pedal is hard to reach during hand maneuvering in the pits, and its just one more obstacle to clean up the tracked in salt in the foot well.
Handbrake is easier to modulate when loading and unloading, and you can reach it through a window/door on the trailer. If you make it strong, (hence a clutch pedal bracket/pivot out of a pickup) you can have a side extension to get it even easier to reach during loading or pit maneuvering. We had the handle curved over so a short extension could slip on, for "outside" braking.
And no master cylinder where its hard to reach or exposed to underhood salt.
JimL