I am using an MTX-L from Innovate with a Bosch LSU4.9 sensor. You cannot replace the original O2 sensor, as this is a standard narrow band sensor with a smaller diameter. So I welded another bung into the header for the LSU4.9. The MTX-L generates a programmable simulation signal for the ECU, which is really helpful. So you can run the engine also in closed loop mode at a different O2 level.
I have a switch installed, were I can change between original O2 sensor signal and the MTX-L simulation signal while riding. The real lambda value can be directly monitored on the MTX-L and I also store it in my selfbuilt datalogger together with all relevant engine information (rpm, ingition timing, amount of fuel, TPS position, temperature, wheel speed, etc.). I will also monitor and analyse the quickshifter functionality now at the Vitpilen, which is new to me compared to the Duke.
The system is quite complex, but very powerful. There is a thread at ktmforum.eu. Look for “Kurze Erklärung zu meinen Messungen”, there you can find some infos to my “development work” with the Duke.