Actually, looking at the manual here, I don't see any reference to CCs at all:
https://cdn.shopify.com/s/files/1/0487/4731/5358/files/gecko_mkiii_manualv1.pdf?v=1607990897
From the product description it's for program changes and tap tempo, and that mentions the CC for tap only.
Without CCs, you won't be able to do channel changes. You could do scene changes in combination with PC Mapping on the Fractal...
If you want a small midi controller, the MorningStar MC-3 would probably be a much better choice...