In trying to fix this I now have numerous things set for "Sw1" and no way to disable them.

Hi, I just tested it on my iPad with iOS 12. I can select "No Mapping". You need to scroll the options wheel slowly. You should be able to choose "No Mappings".

BTW, you can also set Aux Switch mappings on the unit. You can go to the setting mode by pressing and holding the right footswitch and the HOTKNOB.