(I used to use an app called CornerClick for years to do this, but it no longer works in modern macOS)
CornerClick would let you simply CLICK on one of the screens corners (with NO modifier key) to trigger things like Mission Control, Show All Windows, Show All Application Windows, Show Desktop, etc, etc.
No other app lets you do this.
Is there any way you can add this feature to BetterTouchTool? Somebody already requested this feature five years ago, but his thread didn't get any responses.
I’m currently using Butler for this, but Butler only reacts to clicks, not drags. And Butler is ancient.
You can work around this by using the “Move Mouse to Corner” trigger with an extended condition (checking for a pressed mouse button). This works for drags, but it’s not great for clicks because you have to move the mouse before it can trigger again.
At the moment I have the bottom-right corner set to “Show Desktop” in both Butler and BetterTouchTool so I can use both click and drag. Unfortunately, sometimes both apps trigger at the same time - one shows the desktop while the other immediately restores to the state before.
you can configure a left click trigger in BTT (normal mouse section), then add some conditions based on the mouse position to only trigger at the corners of the screen