Just get used to using the piano roll. It's much more flexible than the step sequencer. I use step sequencer for one shots (single wav files like kicks and snares) and the piano roll for slicex'd loops and VST drumkits.
If you really wanted the step sequencer control, you would simply just put multiple MIDI outs to the same MIDI channel (whatever the drum kit is on in Kontakt) and have their default notes set differently. For instance, I have drum kit on MIDI channel three in Kontakt, have four MIDI outs set to channel 3, then set each default note so that each one triggers a different note (trial and error to find the drum sound you have to match the note to). If you look in the channel settings window for each MIDI out you'll see an orange square above the piano. Step sequencers always play C5. If you move the default note to B4 (by RIGHT CLICKING NOT LEFT CLICKING), for example, the step sequencer will play C#5. The distance traveled left with the orange square will be the distance traveled right (pitchwise up) with the sound and the actual trigger. Another example, setting the orange square to A4 will move the triggered note 3 half steps up (because C5 is 3 to the right of the orange square) so it will actually be playing Eb.