See Microtones with the VST2 detune parameter in Kontakt - Dorico - Steinberg Forums.
Dorico is sending the microtonal playback data, but Kontakt 5 ignores it.
Next time some better news maybe Rob?! 
Workaround for all who need it would be: assign the tuning button in the Kontakt Player instrument to a CC number and draw some CC curves within Dorico.