Thanks for your interest. I haven't used any of those plugins yet but if I understand correctly they are always used by side-chaining either MIDI or audio into the plugin (either as a MIDI controlled audio effect or as an audio effect that gets another audio modulation signal as a side-chain input). Unfortunately ALK2 does not yet support side-chaining, but since this feature has already been requested by other users, it's high on our to do list.
ALK2 does support routing multiple MIDI tracks into other MIDI and Instrument tracks - but not as a side-chain input that would be selected inside the plugin. Stay tuned for this in a future update!