I really couldn't see how DAW MIDI input handling on the front end could be VST dependent on the back end, so I tested this with Cakewalk and a few other plugins that I have that are multitimbral and multi-channel MIDI.
SampleTank 3 = same as Kontakt 5
AIR Xpand!2 (uses channels 1-4) = same as Kontakt 5
Dimension Pro (in multitimbral mode using channels 1-4) = same as Kontakt 5
AIR Structure 2 = same as Kontakt 5
Only VSTs with multitimbral mode need to see a specific MIDI channel in order to route the MIDI to the proper instrument slot. I suppose most other VST instruments are actually Omni by default.
I don't have Kontakt 4, so cannot comment on that one. But it seems that the MIDI channel selection in Cakewalk is consistent with any multitimbral VSTi that I tested.
I grabbed a few other plugins that are not multitimbral, and they could care less what channel I am sending MIDI on, as long as the Cakewalk track was set to either Omni, or the actual channel that my controller was set to transmit on.