i don't know if Mitsu did this on purpose, but i like to think that they did.
The steering tie-rod is M12 x 1.5mm threaded rod with 6 flats in the rod at 12mm across the flats, so you use a 12 mm wrench to adjust after loosening the 17mm jam nut.
The distance from the steering pivot to the tie rod is 4 inches, and the distance from the pivot to the rim (where the toe measurement is made) is 8 inches. So there is a 2:1 gain ratio between the adjustment point and the measurement point (e.g. 1mm of adjustment will change the toe-in by 2 mm).
As it works out, with the 1.5mm threads and the 2:1 gain, turning just 1 flat of the tie-rod will move the toe-in by 1 mm. 1 full turn would be 6 flats and that would change the toe-in by 6mm (that would be huge).
This design makes the adjustment so easy for a mechanic to figure--just take the measurement and determine the desired correction in mm, then turn the tie-rod that number of flats.
For example i recently measured 3.5mm on L and 2.5mm on R, so the total was 6mm, which is at the upper limit of the toe-in spec (3 +/-3mm). i wanted to adjust to 0 at the lower spec limit to reduce friction from scrubbing, so i only had to turn in 3.5 flats and 2.5 flats to reach the target.