I played around with the KD-linkage today and found I can EITHER have 1-2 shift at the correct time, OR 2-3.
Not both.

With a nice ca. 10mph 1-2 shift, the 2-3 shifts occur (with light throttle) at an annoying 25-30mph.
Backing off the throttle at say 20mph makes the transmission shift just slightly quicker at 22-23mph.

Adjusting the 2-3 shift to occur at a correct time, will make the 1-2 shift happen at 5 mph or even lower. First gear becomes unusable this way.

This all tells me this transmission does not like the current the KD-lever (or linkage) on my car.

I'm planning to instal or make a longer lever on the transmission to lessen the impact of the throttle movements on the transmission's oilpressure.