Hi David,
I've only had my K49 for a day but I'll have a shot.
If you click on EDIT and then GLOBAL, use PARAM to find the 'Part1 Ch' setting. This controls the keyboard midi out channel as long as you are not using splits.
Now, when it comes to knobs, sliders and pads by default they have hard coded midi channels set to CH1, on the template you want to use 'Upr' which I guess means upper split. If you do that for all controls & Pads it means you can easily change the midi channel for everything via the 'Part1 Ch' setting described above. Don't forget you have to click the value encoder to keep the setting and save your template when done editing the knobs/sliders/pads.
There may be another way to do it, but that's what I'm doing so far
Andy