Sending control+left command with external footswitch, delcom, only picking up control
oh boy, from kinesis [website][4]


  Note: Modifier actions from one USB device
  cannot modify the input of a second USB device due to limitations
  designed into the Apple operating system. Example: Shift, Control,
  Command, or Option keystrokes programmed into the footswitch cannot
  modify the input of a separate USB keyboard or mouse. However, a key
  sequence like ‘Cmd-W’ or ‘Cmd-Shift-left arrow’ will work on a
  Macintosh if the entire sequence of keystrokes has been pre-programmed
  into the footswitch. (Footswitch can only be programmed on a Windows
  PC).


I just tried this using my usb keyboard and built in osx keyboard and it seems to be true.  I can hit control + left on my usb keyboard and it works fine but control on my usb keyboard + left on the builtin keyboard does not work:(

Great news! Karbiner is a mature open source project that allows modifing across devices as a feature.
https://pqrs.org/osx/karabiner/document.html.en


  Share state of modifier keys with all connected keyboards: When you
  are using multiple keyboards, modifier keys are shared with all
  keyboards. For example, pressing "shift key on keyboard1" and "space
  key on keyboard2" sends shift-space.