Tom,
the stock shifter had some problem related to gates for 5th/6th.
When the shifter was in the direction of 5th, the shifter would not fall back to the 3rd/4th rail. Anytime the shifter is put into neutral, it should preload back to 3rd/4th but in this case it would from 1st/2nd but not when the shifter was to the right of 3rd.
It would not spring back and stay off center.
The Kirban quickly returns to 3rd/4th when shifter is released from 5th or 6th gears.
Under high RPMs the shifter would want to edge between 3rd and 5th gear.