I just took a look at the Switch-6 product page. It does not seem like it needs to be powered right? If so, then likely it uses a resistor ladder (like the Strymon multi-switch) so the Helicon can determine what switch is being pressed. The Omniport cannot do this. Omniports are just for MIDI Out, Aux In and Exp In only.
@8buck That was not @james fault. Since I didn’t get a reply on the forum I wrote James an email and that’s how I got the same above answer from him (sort of :))