BetterTouchTool Notch Bar Item Placement
The Notch Bar is split into 4 parts. On the very left is a fixed area that is not scrollable. This is followed by a scrollable area that goes to the left edge of the Notch and another scrollable area that comes right after the Notch. At the end there is again a fixed non-scrollable area on the very right.
The fixed areas have higher priority, this means if you put many items into the fixed left or right areas, the scrollable areas will become smaller.
On standard screens you might not need both of the scrollable areas.