"Trigger on Key Up" shortcut triggering when other keys typed while still held down

To reproduce
Set up two triggers:

  1. set the key, e.g. "e", to trigger some action (say Volume Down) on Key Down.
  2. set the same key to trigger another action (say Volume Up) on Key Up.

Press and hold down the key "e". The volume goes down once, as expected.
While still holding the key, press another key. Each time another key is pressed, the Key Up action is triggered (Volume Up), even though the trigger key "e" is still depressed!

Why am I doing this?
I am using a PCsensor footswitch that is configured to act like a keyboard with one key (I am using F13 but have tested with variety of other keys). I would like it to unmute my microphone when pressed, and mute my microphone when released. However, if I type while the footswitch is held down, BetterTouchTool acts as if the footswitch has been released, breaking this function.

Affected input device (e.g. MacBook Trackpad, Magic Mouse/Trackpad, Touch Bar, etc.): Keyboard


Device information:

  • Type of Mac: MacBook Pro 2016 15"
  • macOS version: 10.13.6
  • BetterTouchTool version: 3.352 (alpha)

Additional information (e.g. StackTraces, related issues, screenshots, workarounds, etc.):